How soon before travel should I see the doctor and get vaccinated?

Ideally you should schedule a visit and start vaccinations at least 6 weeks prior to your trip.

What if I don't have 6 weeks before the trip or need to leave on short notice?

There is an accelerated or compressed schedule for vaccines that may still protect you, so please make an appointment with your doctor and obtain vaccines as described below.

Hepatitis A Vaccine:

  1. If you are less than 40 years of age and healthy, 1 dose of Hepatitis A vaccine (Havrix or Vaqta) any time prior to departure gives some protection. Finish the series upon return for lifelong protection.
  2. If you are greater than 40 years of age, are immunocompromised or have chronic liver disease we recommend 1 dose of Hepatitis A vaccine (Havrix or Vaqta) + Immune globulin 0.02 ml/kg intramuscular injection (at a separate injection site) for protection, any time prior to travel. Finish the series upon return for lifelong protection.
  3. If you are allergic to the vaccine or its components (egg), Immune globulin 0.06 ml/kg intramuscular injection any time before trip likely provides protection for 3 months.

Hepatitis B Vaccine:

  1. Hepatitis B vaccine (Engerix-B or Recombivax-HB) can be administered on days 0, 7 & 14 before travel and a subsequent booster given at 6 months for lifelong protection.
  2. A combination Hepatitis A & B vaccine (Twinrix) that can be administered on days 0, 7 & 21 before travel is also available with a booster given at 12 months for lifelong protection.

Japanese Encephalitis Vaccine:

Japanese encephalitis vaccine is given on days 0 & 28 before travel. If there is ongoing risk a single booster can be given at 24 months.

Measles Vaccine:

  1. A single dose of measles vaccine (MMR II) can be given to adults at any time before travel; it is recommended for individuals born in or after 1957, vaccinated before 1980 or have not had physician diagnosed or blood antibody evidence for prior measles illness.

Meningococcal Vaccine:

  1. A single dose of Meningococcal vaccine (Menomune or Menactra) can be given at any time prior to travel.

Polio Vaccine:

  1. If previously vaccinated, a single dose of IPV (inactivated polio vaccine) is administered any time before travel to countries at risk.
  2. If the traveler has never had Polio Vaccine before, we recommend 1 dose of IPV any time prior to trip and finish 2 more doses 4 weeks apart upon return.

Rabies Vaccine:

  1. Rabies Vaccine (Imovax or RabAvert) pre-exposure vaccination is given on days 0, 7 & 21 prior to travel. One does require post exposure vaccination if exposed to a rabid animal; 2 more vaccine doses separated by 3 days is recommended in this situation.

Tetanus, Diphtheria and Pertussis Vaccine:

  1. If previously vaccinated, a single dose of Tdap (Adacel or Boostrix) can be administered any time before travel if no booster has been given in past 10 years.
  2.  If not previously vaccinated or not sure of status, doses of Tdap can be administered on days 0 & 28 prior to travel and receive the final dose in 6-12 months.

Typhoid Vaccine:

  1. A single dose of Typhoid vaccine (Tyhim Vi) can be given any time before travel.

Yellow Fever Vaccine:

  1. A single dose of Yellow fever vaccine (YF-Vax) can be given a minimum of 10 days prior to travel. If there is ongoing risk of exposure a booster dose is given every 10 years.

What is the best insect repellant to use?

DEET: The most effective and well researched insect repellant is DEET ((N, N diethyl-m-toluamide). It comes in concentrations ranging from 5% to 100%. The higher concentrations give you longer duration of protection, not more efficacy, but can increase the risk of side effects.

Concentrations of up to 50% are safe and effective for up to 6-8 hours. Repellant effects lasts longer on clothing than skin, so long sleeve shirts and pants are helpful and it prevents toxicities since only a small proportion of exposed skin has DEET on it. We recommend that you wear long sleeve shirts and pants, spray insect repellant containing DEET to clothing and any exposed skin.

Avoid spraying repellant on mucus membranes (eyes, mouth etc.) to avoid toxicity.

Picaridin: Picaridin is an insect repellant that may be as effective as DEET with less irritating side effects and preparations sold in Europe and Australia are effective for up to 8 hours. However the product sold in the US (Cutter Advanced) has lower concentration and is effective for 1-4 hours.

How effective are organic or ‘natural’ insect repellants?

Insect repellants made from eucalyptus – eucalyptol, lemon grass – citronella, catnip – nepetalactone are all effective to some degree. However independent studies show that for ecalyptol & citronella their effectiveness is very short lived; 30 -60 minutes and nepetalactone is ineffective once applied to skin.

What is the worry about DEET?

DEET may cause seizures in some people, especially children; to date there has been 14-46 cases, with 4 deaths reported. This risk works out to 1 in 100 million users in the United States perhaps worth the benefit.

How important is it to wash hands while traveling?

It is absolutely critical to wash hands, nearly all diarrhea illnesses and many upper respiratory infections are transmitted through contaminated hands. We suggest that you use soap and clean water (bottled water is readily available in developing countries) to wash hands thoroughly.

Are hand gels useful to clean hands while traveling?

Ideally one should try to wash hands with soap and clean water, but this may not always be practical.In those circumstances, if the hands are not visibly dirty or if you can wipe of all dirt, one could use a hand gel with at least 60% alcohol to clean hands.

How do I prevent blood clots while flying?

What can be done to prevent formation of blood clots while traveling?

  • Wear loose fitting clothing
  • Walk around the airplane at regular intervals if possible
  • Exercise your legs by bending and straightening your feet and knees.
  • Avoid crossing of your legs.
  • Drink plenty of liquids.
  • Avoid alcohol – it dehydrates your body
  • Wear properly fitted graduated compression stockings

Are there any medications that can be taken to prevent blood clots while traveling?

Individuals with a prior history of blood clots or those at high risk for blood clots may benefit from taking medications prior to long flights.

Those individuals with 2 or more of the following risk factors and flying more than 8 hours at a single stretch should consider taking a dose of low molecular weight heparin (1mg/kg of ideal body weight) up to 12 hours before flight.

  • Major surgery within 6 weeks.
  • Hip or Knee replacement within 6 weeks.
  • Obesity.
  • Age greater than 65.
  • Hereditary Clotting Disorders.
  • Previous Blood Clot.

Check with your physician to evaluate your risk and take medication if appropriate.

How do I prevent or deal with Jet lag?

What can be done to prevent jet lag?

  • During flight avoid large meals, drink plenty of liquids to keep hydrated, avoid alcohol, caffeine and carbonated beverages.
  • When you get to your destination, increase your outdoor activities to get maximal sunlight exposure. Bright outdoor light will help you shift your daily clock sooner.
  • Stay awake during daylight hours.
  • Adjust all your activities and meals to the new time zone.
  • If you absolutely have to sleep during the day, just take a nap for 45 minutes at most.

Are there any special diet’s that will help?

  • A high protein breakfast can increase levels of hormones that promote alertness and keep you awake.
  • A high carbohydrate dinner can increase hormones that promote sleepiness.

Is melatonin helpful in preventing jet lag?

  • Melatonin taken at a dose of .05 - 5mg may be helpful for some if crossing more than 5 time zones. It should be taken at the desired bedtime you hope to have at your destination; starting 3-4 days prior to travel. This may not be practical for many travelers.
  • The manufacturing process for melatonin is not standardized and dosages fluctuate widely in different preparations.
  • Its safety in those suffering seizures, children and in those taking blood thinning medications like Coumadin is not established.

What about other medications?

  • Sedatives like ambien (zolpidem) and lunesta (zopiclone) may be helpful in prolonging sleep at your destination.
  • Short acting benzodiazepine class of medication like restoril (temazepam) may also be beneficial.
  • The side effects of above may not be worth any benefit you gain, speak with you physician.
  • DO NOT combine melatonin with above medications.

What about ‘red bull’ and other stuff to keep me awake?

Stimulants like caffeine, amphetamines or amphetamine like products can interfere with sleep patterns, can be habit forming and are not recommended.

So what is the bottom line in dealing with jet lag?

The best way to deal with jet lag is to be well rested prior to the trip, stay hydrated during the trip, avoiding stimulants (caffeine) and sedatives (alcohol) and adjust your activities, meals and sleep strictly to the new time zone with as much exposure to outdoor light as possible , and avoid day time sleeping.

Is it alright to take an anti-diarrhea medication for traveler's diarrhea?

Yes, studies have found that a combination of an antibiotic plus an anti-diarrheal like Loperamide (lomotil) was more effective in decreasing the duration of illness than with antibiotics alone.

What countries in the world are at risk for Malaria?

While malaria is reported in over 100 countries in the world, the greatest risk of acquiring it is from Africa, India, Vietnam, Sri-Lanka, Brazil, Columbia and the Solomon Islands.

What countries in the world are at risk for Yellow Fever?

The disease occurs mainly in tropical parts of Africa, South and Central America.

Are there certain vaccines that are absolutely required by a country to visit it?

Yes, there are 2 vaccines that are required and for which you need to show written proof to be allowed entry to certain countries.

a) Meningococcal Vaccine:  Saudi Arabia requires that you be vaccinated with the quadrivalent (A/C/Y/W-135 ) vaccine given no more than 3 years and no less than 10 days before arrival for the Hajj & Umrah pilgrimage

b) Yellow Fever Vaccine:  The following countries require yellow fever vaccination and certificate from all travelers:

  • Angola
  • Congo
  • Rwanda
  • Benin
  • Cote de’ Ivoire
  • Sao Tome & Principe
  • Burkina Faso
  • French Guiana
  • Sierra Leone
  • Burundi
  • Gabon Togo
  • Cameroon
  • Ghana
  • Central Africa Republic
  • Niger

Many countries require yellow fever vaccination and certificate if coming from countries at risk of yellow fever 6 days prior; even if you were there only in transit.You can find about the specific country requirements by going to that country page using our search function.

Tell me more about Altitude sickness?

Altitude sickness is a spectrum of illness ranging from mild symptoms of headache, fatigue, nausea to life threatening respiratory failure, seizures and coma associated with change in altitude. Altitude sickness is usually seen at heights of 8000 feet or higher, but can be seen at elevations as low as 4000 feet.

The illness corresponds more to the speed with which you climb or change altitude than with a specific altitude. For example driving from sea level to an altitude as little as 4000 feet high in a few hours might make you ill as opposed to reaching 8000 feet over a period of 2-3 days.

Altitude sickness occurs from traveling to a higher altitude quicker than the body can adapt to the lower oxygen concentration at that altitude, resulting in fluid leaking from blood vessels into tissues resulting in the symptoms of severe altitude sickness like shortness of breath at rest, headache, fatigue, lethargy and coma. The lower concentration of oxygen at higher altitude also means that there is increased work of breathing to carry out the same activities

Can one predict who will get altitude sickness?

There are no specific risk factors or tests that can predict who will succumb to altitude sickness; in particular physical fitness or conditioning does not decrease the chance of sickness. Past performance at altitude may be the only predictor of future events, but even this is not fool proof.

Are there any medical conditions that are a cause for concern?

Individuals with underlying medical conditions involving the HEART (congestive heart failure, angina), LUNG (COPD: asthma, emphysema, chronic bronchitis), or SICKLE CELL DISEASE are at increased risk of illness and need to gradually ascend to better acclimatize. People with DIABETES could go into a complication called ketoacidosis due to altitude sickness. If you had radial keratotomy surgery on the eye you could develop sudden far sightedness; Lasik procedures do not have this issue. Please consult your physician prior to undertaking a trip to altitude.

What are the categories of Altitude Sickness?

There are three well defined syndromes of Altitude Sickness:

  • Acute Mountain Sickness (AMS).
  • High Altitude Pulmonary Edema (HAPE).
  • High Altitude Cerebral Edema (HACE).

What are the signs and symptoms of Altitude Sickness?

  • Acute Mountain Sickness: Signs and Symptoms of acute mountain sickness are headache, nausea, vomiting, fatigue, dizziness or difficulty sleeping. These are usually seen 6-12 hours after arrival to high altitude 
  • High Altitude Pulmonary Edema: Signs and symptoms of High Altitude Pulmonary Edema include breathlessness that does not improve with a few minutes of rest, cough, weakness, chest tightness, rales or wheezes on lung exam (crackling or musical noise), blue lips or fingernails, rapid breathing, rapid heartbeat.
  • High Altitude Cerebral Edema: Signs and symptoms of High Altitude Cerebral Edema include those of Acute Mountain Sickness plus lethargy, hallucinations, confusion, seizures or focal neurological deficits.

    A simple test is to ask the person to walk in a straight line with toes touching the heel of the other foot with each step (the driving under influence of alcohol- police walk!); if they are unable to do this and wobble like a drunk they have high altitude cerebral edema.

How Can One Prevent Altitude Sickness?

  • Ascent gradually from sea level 
  • Spend 1-2 days acclimatizing at 8000-10,000 feet (2500-3000m). 
  • As you go higher from 8000-10,000 feet (2500-3000m), spend an extra night for each 1000-3000 feet (300 - 900m) that you climb.
  • Drink plenty of fluids and eat snacks frequently.
  • Avoid alcohol.
  • Take slow, small steps instead of rapid, long strides and rest frequently.
  • Medications: If you have had previous problems with altitude and do not have the time to slowly acclimatize, medications are available for use in preventing or treating high altitude sickness.

    a. Acetazolamide (Diamox) 125 mg tablet taken every 12 hours, starting the day of ascent can be beneficial in preventing acute mountain sickness. The dose can be increased to 250 mg every 8 hours as well based on studies, but side - effects of numbness and tingling of limbs may occur. Drink plenty of fluids to compensate for increased urination that can happen with this medication to prevent dehydration. Check with your doctor to see if this is right for you.

    b. Nifedipine (Procardia) 10-20 mg every 8 hours has been shown to be helpful in preventing or treating High Altitude Pulmunory Edema in susceptible individuals.

    c. Sildenafil citrate (Viagra) may also be beneficial in preventing or treating High Altitude Pulmunory Edema in susceptible individuals.

    d. Dexamethasone 4 mg every 6 hours has also been shown to be beneficial in preventing or treating Acute Mountain Sickness or High Altitude Cerebral Edema. However if the medicine is stopped one can experience sudden worsening of symptoms.

    e. There are conflicting studies as to the effectiveness of the herbal supplement Ginkgo Biloba in preventing altitude sickness; typical doses are 120 mg once a day starting two weeks before ascent and continued throughout.

What is the treatment for Altitude Sickness?

  • The first, most effective and most important treatment measure is returning to lower altitude.
  • Seek medical attention to diagnose which of the three syndromes you have and initiate specific treatment with the following medications:

    a. Acetazolamide (Diamox)
    b. Nifedipine (Procardia)
    c. Dexamethasone
    d. Sildenafil citrate (Viagra)

  • Use of a portable pressure bag called Gamow bag, operated by a foot pump to increase pressure inside that simulates a descent of 5000-6000 feet (1500-1800m) can be used when descent to lower altitude is not feasible.

What do I do about Bites and Stings?

Bites from domestic animals, wild critters and snakes or stings from bees, wasps, spiders, scorpions and jelly fish can ruin a trip; but more importantly is potentially dangerous and even life threatening.

In the developing world all domestic dogs are considered to be potential sources of rabies and any bites need to be cared for immediately with administration of rabies vaccine.

Similarly, poisonous snakes are prevalent and lack of refrigeration and good medical care makes availability of anti-venom and supportive care scarce.

If you have experienced anaphylaxis from insect stings previously, carry your own medical kit for treatment (Ana-Kit, Epi-Pen)

Therefore an ounce of prevention never mattered as much as in avoiding bites and stings.

What can one do to prevent animal bites and insect stings?

In general travelers should take the following precaution to avoid:

Animal and Snake bites

  1. Avoid petting, handling or feeding domestic or wild animals
  2. Supervise young children at all times when around animals
  3. To avoid snakebites minimize rural outdoor activities at dusk and dawn when snakes are most active. Wear long pants and shoes when walking.

Insect stings

  1. Wear long sleeve shirts, pants and shoes.
  2. Apply insect repellant containing DEET to clothing and exposed skin.
  3. Avoid cosmetics, perfumes and hairspray – these attract insects
  4. Wear dark or tan colored clothing – these are less attractive to insects compared to bright or white colors.
  5. Food odors can attract insects, careful with outdoor cooking.
  6. Stay in screened accommodations, preferably with air-conditioning.

Jelly fish stings

  1. Check with the locals and avoid jelly fish infested waters.
  2. Wear ‘stinger suit’ – full body Lycra swimsuit in jelly fish infested waters.

What should you do if you have been bitten or stung?

Animal Bites: Dogs, Cats, Bats, Skunks, Raccoons, Monkeys

  1. Immediately clean wound with safe water (bottled, purified, boiled) and soap or detergent.
  2. Promptly seek medical attention for wound care.

    a. Facial wounds will likely need suturing after copious irrigation and cleansing.
    b. To reduce risk of infection all other wounds are best treated by not suturing and letting the wound close by itself after copious irrigation and cleansing. If wounds are complicated or very deep it may need to be sutured minimally.

  3. Rabies vaccinations should be instituted for most animal bites occurring in the developing world.
  4. Prophylactic antibiotics should be started to reduce risk of infection. A broad spectrum agent like Augmentin would be preferred.
  5. Tetanus booster should be updated. All travelers should update this prior to travel.
  6. If the bite is from a macaque monkey, in addition to the above recommendations, one should also start Acyclovir 800 mg by mouth 5 times a day for 14 days to prevent Herpes- B virus infection.

 Snake Bites:

  1. Seek medical attention IMMEDIATELY
  2. On your way to the medical facility, gently immobilize the affected limb with a splint or bandage that does not restrict blood flow.
  3. DO NOT apply tourniquet, attempt to cut open the area of bite or “suck out” poison. This is NOT a Hollywood movie shoot!!
  4. The local medical personnel will need to address issues of anti-venom, steroids, histamine blocking agents etc.
  5. Prophylactic antibiotics are indicated to prevent infection, at least in the beginning. A broad spectrum agent like Augmentin is preferred.

Insect Bites: Bees, wasps, spiders, scorpions

  1. Mild local reaction – pain, swelling, redness at site of sting

    a. Treat with pain medications (Tylenol or Motrin) and cold compresses

  2. Large local reaction – Large area of redness, swelling, nausea and fever

    a. Treat with cold compresses, aspirin or Motrin for anti-inflammatory effect.
    b. Benadryl 25-50 mg every 6 hours as needed and if severe Prednisone 40 mg/day for 3 days.

  3. Anaphylaxis – red rash, flushing, swollen lips, breathing difficulty, shock

    a. You should use your anaphylaxis treatment kit (Ana-kit, Epi-Pen) and seek immediate medical help. It is important to get medical attention since you can develop delayed symptoms once the immediate treatment effects wear off.
    b. Some spider bites may benefit from the use of the antibiotic Dapsone 50 mg/d, specifically the brown recluse spider bite.
    c. Issues of anti-venom are best discussed with your physician.

Jelly Fish Sting

  1. Wash area with vinegar to prevent further discharge of stinging cells.
  2. Seek immediate medical attention.
  3. Anti-venom is available in certain countries.

What are the health reasons not to travel by air?


  • Unstable angina or chest pain at rest
  • Uncomplicated heart attack within the past 3 weeks
  • Complicated heart attack within the past 6 weeks
  • Congestive heart failure or breathless with minimal effort or at rest
  • Uncontrolled high blood pressure


  • Collapsed lung or pneumothorax treated within the past 3 weeks
  • Breathless with minimal effort or at rest


  • Active infection of ear, nose or sinuses
  • Ongoing contagious disease


  • Coronary Bypass or Heart surgery within the past 2 weeks
  • Facial, Eye or Neurological surgery within the past 2 weeks
  • Chest or Abdominal surgery within the past 2 weeks


  • Stroke within the past 2 weeks


  • Anemia with a hemoglobin level <8.5 gm and sickle cell disease or trait.


  • Single dive per day of less than 2hrs within the past 12 hours
  • Multiple unlimited dives per day with the past 24 hours

How clean is the air on airplanes?

Air in the cabin of commercial airlines is recycled on average 20 to 30 times per hour and passes through sophisticated HEPA filters.

Therefore air in the cabin of commercial airplanes carry less concentration of germs than seen at shopping malls, theaters, churches or airport terminals.

Despite this fact, approximately 26% of air travelers report contracting a respiratory illness after travel. It is not clear if the illness was contracted in the air or during activities on the ground at terminals when one is around large crowds.

However, there have been documented cases of in-flight transmission of measles, influenza, tuberculosis and SARS. The risk of transmission was associated with sitting in the same row or section as the infected person.

Blankets and pillows are not routinely sterilized or washed in between flights; they can be a source of spreading germs.

The Centers for Disease Control does not recommend routine wearing of masks. Strict hand washing is the single most important measure in preventing transmission of respiratory illnesses, because respiratory pathogens attach to surfaces everywhere.

Avoiding air travel by ALL those who are ill is probably the best overall advice for all of us.

How do I deal with motion sickness?

Come on everybody, let’s do the loco motion’
Yeah! It’s a bad joke!

Motion sickness is an illness that occurs when information sent to the brain about one’s position or movement is conflicting, thus resulting in a feeling of unsteadiness. These conflicting signals seem to affect the normal gastric motility resulting in delayed emptying. The inner ear is the most critical organ in sending these signals to the brain but the eyes and propioreceptors also play a role.

It is most common during travel by boat in rough waters followed by air, car and train travel. The symptoms are also worst with travel in boats followed by air, car and train travel.

What are the signs and symptoms of motion sickness?

Sign and symptoms are an uneasy, queasy feeling in the stomach, dry heaves, nausea, flushing, sweating, excessive salivation, dizziness and finally vomiting.

Are some people more prone to motion sickness?

It is hard to predict individual susceptibility to motion sickness, however it is more commonly seen in women especially if pregnant or having menses, children below 12 years of age and people who suffer from migraine headaches.

What can be done to prevent motion sickness?

  • Stay in a central location on the boat.
  • Sit by the window seat in the midsection of the airplane.
  • Sit in the front seat of the car.
  • Sit in the forward cars of the train.
  • Reduce head and body movements to a minimum.
  • Preferably keep your eyes closed or look at distant objects. 
  • Avoid reading or looking at things inside the vehicle - ‘by keeping your eyes closed!’
  • Decrease food intake.
  • Avoid alcohol.
  • Lay down flat on your back.

What about medications to prevent motion sickness?

The following medications have been used to prevent or treat symptoms of motion sickness in adults.

  • Scopolamine patch 1.5 mg (Transderm-scop, Scopace) Apply to bare skin behind the ear, a minimum of 4 hours prior to trip. Remove or put a new one on as needed every 72 hours. If you cut the patch in half it will be useless. Scopolamine tablets 0.4 – 0.8 mg every 8 hours, take it 1 hour before travel.
  • Meclizine (Antivert, Bonine, Meclicot, and Medivert) tablets 25-50 mg once every 24 hours; take it 1 hour before travel.
  • Cyclizine (Marezine) 50 mg tablet every 4-6 hours as needed, not more than 200 mg in 24 hours; take it 30 minutes prior to travel.
  • Dimenhydrinate (Dramamine, Triptone, and Calm X) tablets 50 - 100 mg every 4-6 hours as needed, not more than 400 mg a day; take it 30 minutes prior to travel.
  • Promethazine (Phenergan, Promacort) 25 mg tablet by mouth, injection or suppository every 8-12 hours as needed; take it 30 minutes prior to travel. This medication can make one intensely drowsy and we do not recommend it to prevent motion sickness, but may be useful in treating severe vomiting associated with motion sickness.

All of the above medications can impair your psychomotor functions, interact with other medications, have other side effects and need to be closely discussed with your physician prior to taking them.

What about alternative remedies to prevent motion sickness?

  • Ginger candy has been used with varying success.
  • Wrist bands that put pressure on the mid portion of the wrist have also been used with varying success.

What about scuba diving safety?

Medical complications of diving are extremely rare, with the Divers Alert Network reporting only about a 1000 injuries among nearly 9 million scuba divers in the United States. However, nearly 10% of these injuries result in death. Medical Practitioners are not well versed in the diagnosis and treatment of these disorders due to its rarity and divers need to take responsibility for recognizing the symptoms and signs of dive related medical complications.

  • Medical complications of diving can be broadly categorized into
  • Barotrauma
  • Decompression syndrome
  • Nitrogen narcosis
  • Hypothermia

What is the mechanism of diving injuries?

The crux of the problem is explained by two laws of physiology:

Boyle’s law – when it comes to gases, volume is inversely related to the pressure; meaning at higher atmospheric pressures the volume of gas decreases and at lower atmospheric pressure the volume of gas increases.

Atmospheric pressure increases as one dives underwater, and the volume of gas decreases. As one dives, the decreasing volume of gas in a space like the ear, sinuses or lungs can result in swelling of tissues, engorgement of blood vessels and bleeding into the ear, sinus or lungs.

Conversely as one ascends, atmospheric pressure drops and the volume of gas expands. Rapid ascents can lead to the volume of gas expanding by nearly 30% which leads to rupture of ear drum, sinus or lung tissue.

Medical complications of this nature are classified as Barotrauma.

Henry’s law– the amount of gas dissolved in a liquid is directly proportional to the pressure on that gas; meaning that at higher atmospheric pressure the tissues of the body become more concentrated with oxygen and nitrogen.

As one dives deeper into the ocean, usually at depths of 100 feet or more the high concentration of nitrogen in the nervous system can lead to dulling of thought, lack of coordination, altered behavior and even loss of consciousness.

Conversely rapid ascents with resulting decrease in atmospheric pressure can lead to nitrogen gas escaping from tissues as gas bubbles. This results in symptoms of joint pains, itching of the skin or more serious complications of the nervous system with paralysis, difficulty walking (‘staggers’) personality changes etc. Pulmunory symptoms of chest pain, shortness of breath, etc. may also be seen.

\Medical complications of this nature are categorized as decompression syndrome.

What are the signs and symptoms of barotrauma?

  • Ear : symptoms are of ear pain, dizziness, nausea and disorientation.
  • Sinus: symptoms are of pain in the sinus area and headaches. Commonly the frontal sinus is involved and one experiences pain on the forehead above the nose.
  • Lung: Lung injury that occurs due to decreased volume of gas as one descends leads to symptoms of shortness of breath, cough and bloody phlegm.
    Lung injury that occurs due to expansion of the volume of gas as one ascends and leads to rupture of lung tissue and leakage air results in symptoms of shortness of breath, chest pain, cough, hoarseness, difficulty swallowing and swollen tissues around the neck and chest.
    Arterial gas embolism is the most serious complication of lung injury resulting from the formation of gas bubbles.
  • Dental: As the volume of air changes around cavities and fillings, it can lead to pain and rarely ejection of the filling.
    When gas bubbles enter the arterial blood supply and reach individual organs, they can become lodged at the endpoints of circulation and cause symptoms that are dependant on the organ affected.
  • Skin: bluish lace like discoloration of skin
  • Kidney: blood in the urine
  • Gastrointestinal System: bleeding from the rectum or throwing up blood
  • Heart: heart attacks, irregular heart rhythms and cardiac arrest.
  • Central Nervous System: numbness and tingling of one side of the body, paralysis of one side or half of the body, difficulty seeing, seizures, loss of consciousness and death.

What are the signs and symptoms of Decompression sickness – “The bends”?

As one ascends the nitrogen is released from tissue and cause symptoms depending on the organ involved.

  • Bones: Joint pains can be seen particularly in the elbow and shoulder but also in the hips and knees. This can be seen in the first hour after ascent but sometimes is delayed up to 1-2 days.
  • Skin: Itching, color changes and sometime small bubbles can be seen.
  • Nervous System: Changes in sensation, paralysis, loss of coordination, memory loss, and visual changes are sometimes seen.
  • Lung: Shortness of breath, wheezing, cough, heart failure and death can occur.

What are the signs and symptoms of Nitrogen narcosis?

As the atmospheric pressure rises, typically with dives of more than 100 feet, more nitrogen dissolves in body tissues and the effects are more pronounced on the nervous system. One develops personality changes, lose of ability to think clearly, and loss of motor coordination. This can lead to hallucinations, loss of consciousness and death.

What are the signs and symptoms of Hypothermia?
Symptoms include shivering, clumsiness, and can lead to serious life-threatening events. This has been controlled by the addition of wet and dry suits.

What are the contraindications to scuba diving?

  • Pregnancy
  • Lung disease: COPD, asthma (if stable and normal pulmonary function tests risk is diminished), bronchiectasis, cystic fibrosis, interstitial lung disease, previous pneumothorax, previous lung surgery
  • Heart disease: severe coronary artery disease, arrhythmias, congenital heart disease, patent foramen ovale
  • Nervous System: seizures, stroke, head injury, unstable psychological disease, drug abuse
  • Gastrointestinal: unrepaired hernia
  • Diabetes mellitus
  • Perforated ear drum
  • Blood disorders: leukemia, haemophilia

What preventive measures can be taken?

  • Barotrauma
    Do not dive with active ear or sinus problems
    Keep breathing – never hold your breath especially on ascending
    Perform equalization techniques frequently – such as yawning, pinching the nose with swallowing/exhaling, head tilting, etc .
  • Decompression sickness
    Strictly following dive charts
    Do not fly for at least 12 hours after simple dives
    Do not fly for 48 hours after multiple dives or dives requiring decompression
  • Nitrogen narcosis
    Limit depth of dives (less than 60 ft)
    Education and use of various gas mixtures

Can the complications be treated?

  • Barotrauma
    Drain fluids from middle ear for ear barotrauma
    Antihistamines and decongestants maybe helpful for sinus barotrauma
    Oxygen therapy and chest tube drainage maybe needed for lung barotrauma depending on severity of findings.

  • Decompression sickness
    The most effective treatment is recompression and oxygen treatment in a hyperbaric chamber.
    IV fluids, lying on the left side of the body with upper part of body slightly lower than the legs are helpful

  • Nitrogen narcosis
    Ascend from deep water to a shallower depth

Who to contact in an Emergency?

(DAN) Divers Alert Network – 1-800-446-2671.

How do I stay healthy on an airplane?


Keep yourself hydrated by drinking plenty of water and fruit juices. Avoid alcohol and carbonated soft drinks.


Prevent bloating by eating light meals and avoiding green vegetables, beans and soft drinks. Yes! Your health can handle missing an airline supplied green vegetable!!

Prevent blood clots

Prevent blood clots by exercising your feet and legs frequently. Bend and straighten your feet and knees every 10 minutes for 1-2 minutes. Wearing properly fitted graduated compression stockings are also helpful.

Prevent jet lag

Reduce jet lag by resting well, hydrating well, eating light and avoiding alcohol.

Dealing with congestion

If you have or recently had an upper respiratory infection or sinusitis, consider taking an oral (Sudafed) and/or nasal decongestant (Afrin) prior to flight.

Dealing with motion sickness

Sit by the window seat in the middle part of the aircraft. Keep your eyes closed or focus on the horizon if visible, avoid reading or watching movies. Consider taking Antivert, Scopolamine patch or Dramamine prior to flight if this has been a problem previously.

Dealing with ear pain

To equalize pressure in the ears, chew gum or suck on candy while descending from altitude.

Staying warm & healthy

Avoid airline supplied blankets and pillows, these are not sterilized or cleaned in between flights, you are likely to snuggle up to someone else’s germs. To stay warm bring your own blanket or jacket and invest in a small air pillow.

Avoiding colds

If you are worried about catching a cold while flying, if possible avoid sitting next to someone who is ill; without making a big scene. You might consider wearing a mask yourself, although it might make everyone else worry that you have something bad!

Viral particles can be deposited on surfaces; one might consider wiping off arm rests, drop down tables and overhead bins with alcohol wipes.

Wash hands with soap and water or antiseptic gels that have greater than 60% alcohol before eating and drinking.

Avoid touching your nose and mouth, since germs are introduced into the respiratory tract this way.

Turn on the overhead fan at low and point the nozzle to the front of your face, the air turbulence might keep viral particles from coming your way.

Avoid airline supplied blankets and pillows, these are not sterilized or cleaned in between flights, merely refolded; you are likely to snuggle up to someone else’s germs.

If these suggestions do not inspire confidence, we can only suggest you drive; with seat belts on and at or below the speed limit. Bon Voyage !!

What if I already had vaccines?

Many travelers are not first time travelers, but are infrequent travelers. Do they need to repeat their vaccinations every time they travel or is once enough?

Unfortunately, this differs for every vaccine. So we have included this section to verify how often booster injections are recommended.

It is best to keep a recorded record of vaccinations for this reason and to verify if asked by immigration & customs in visiting countries

Vaccine & Booster

  • Tetanus/Diphtheria: Td every 10 yrs
  • Hepatitis B: after 3 injections lasts approx. 15 yrs
  • Polio: one lifetime dose prior to travel
  • Hepatitis A: after 2 injections, 10 yrs
  • Influenza: annually
  • Japanese encephalitis: after 1 yr, then every 3 yrs
  • Pneumococcal: consider after 5 yrs
  • Typhoid fever: every 3 yrs for Vi CPS, 6 yrs for Ty21a
  • Yellow fever: 10 yrs

What is Traveler's Diarrhea?

Traveler’s diarrhea is a clinical syndrome of diarrhea, abdominal cramps, sometimes nausea, and vomiting and low grade fever caused by a variety of pathogens including bacteria, viruses, parasites and even pre-formed toxins. Therefore this syndrome does not indicate a specific pathogen, rather the way you acquired the illness; by travel, thus traveler’s diarrhea. Travelers’ diarrhea is the most common illness in individuals traveling from developed countries to developing countries; being seen in nearly 40 – 60% of travelers. Even though it infrequently leads to serious complications and most illness can resolve by itself, even mild to moderate illness can ruin one’s enjoyment of the trip, wreck schedules, frustrate leisure or business activities and make one terrified about finding a toilet in places where restrooms are not readily available or worse the sight of which can make you even sicker. Dehydration resulting from fluid losses and inability to keep fluids in due to vomiting poses the biggest health problem to travelers.

For more information, please visit our Traveler's Diarrhea section.

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