Who is susceptible to altitude sickness

Evidence-based emergency medicine. Update: do ophthalmic nonsteroidal anti-inflammatory drugs reduce the pain associated with simple corneal abrasion without delaying healing? Turner A, Rabiu M. Patching for corneal abrasion. Cochrane Database Syst Rev. Refractive changes during hour exposure to high altitude after refractive surgery. Alexander JK. Coronary problems associated with altitude and air travel.

Cardiol Clin. How well do older persons tolerate moderate altitude? Effects of exposure to altitude on men with coronary artery disease and impaired left ventricular function. Am J Cardiol. Hultgren HN. Effects of altitude upon cardiovascular diseases. Splenic syndrome at mountain altitudes in sickle cell trait. Its occurrence in nonblack persons. The sickle-cell and altitude. Br Med J. Brubaker PL. Adventure travel and type 1 diabetes: the complicating effects of high altitude.

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Sign Up Now. Previous: Management of Influenza. Next: Evaluation of Microcytosis. Nov 1, Issue. C 5 , 7 — 11 Expert opinion Medications for prevention and treatment of acute mountain sickness and high-altitude cerebral edema include acetazolamide and dexamethasone. B 8 , 16 — 19 , 29 Small RCTs, meta-analysis Descent is mandatory in persons with high-altitude cerebral or pulmonary edema.

C 4 , 7 , 8 , 21 , 26 , 27 Expert opinion Prophylaxis with salmeterol Serevent , nifedipine Procardia , dexamethasone, or phosphodiesterase-5 inhibitors tadalafil [Cialis], sildenafil [Viagra] may reduce the incidence of high-altitude pulmonary edema. B 24 , 25 Small RCTs Uncontrolled congestive heart failure, severe chronic obstructive pulmonary disease, and pulmonary hypertension are contraindications to altitude exposure. C 42 — 44 — Activity restriction at high altitudes is not necessary in patients with stable coronary artery disease.

Enlarge Print Table 1. Recommendations for Acclimatization at High Altitudes Avoid flying or driving to high altitudes unless necessary. Do not ascend if you have symptoms of altitude illness. Descend if symptoms do not improve within 12 hours. Be aware that persons acclimatize at different rates. Table 1. Acute Mountain Sickness Worksheet Figure 1. Enlarge Print Table 2. Table 2. Enlarge Print Table 3. Table 3. Enlarge Print Table 4. Chronic Conditions Affected by Altitude Exposure Condition Recommendation Arrhythmias There is a lower threshold for increased incidence of arrhythmias at high altitudes; provide supplemental oxygen and limit activity.

Asthma Exacerbation does not seem to be related to altitude; continue usual treatment. Chronic obstructive pulmonary disease Risk is dependent on disease severity; consider pulse oximetry and adjust supplemental oxygen as needed. Patients with severe disease should not travel to high altitudes. Congestive heart failure Risk of decompensation depends on disease severity, activity level, and elevation; supplemental oxygen may need to be increased.

Coronary artery disease Individualized evaluation is necessary; provide appropriate chemoprophylaxis e. Hypertension Mild, transient elevations in blood pressure are expected and do not require treatment; maintain blood pressure control at sea level and continue all medications. Pulmonary hypertension Travel to high altitudes is contraindicated in patients with pulmonary hypertension because of the hypoxic environment and risk of high-altitude pulmonary edema; if travel is necessary, calcium channel blockers, isoproterenol, and supplemental oxygen may be beneficial.

Sickle cell disease Travel to high altitudes is contraindicated because of the increased incidence of splenic infarct and sickle cell crisis. Table 4. Read the full article. Get immediate access, anytime, anywhere. Some people cough up blood and retain fluid in their lungs as the pressure inside capillaries increases, forcing out water. The U. Army Research Institute of Environmental Medicine estimates that above 3, meters between 25 and 35 percent of soldiers yield to altitude sickness; above 4, meters, between 80 and 90 percent of soldiers fall ill.

Although there are effective drugs like Diamox acetazolamide to prevent and treat altitude sickness, buying drugs in mass quantities for an unknown number of soldiers is expensive and wasteful, and some drugs have unwanted side effects such as blurred vision and excess blood acidity. A genetic test would not help treat altitude sickness, but it would help military leaders strategize, giving the soldiers most likely to get sick more time to acclimatize and thereby reducing the number of medical evacuations.

Bloated bovines Altitude sickness is also the scourge of entirely different population of mountain-dwellers: cows. By the time a rancher spots one lumbering up and down the mountain, its swollen chest sloshing between its front legs, there is not much he can do except move the animal to a lower altitude and hope it lives. Every summer in the U. West—when ranchers take cattle to graze on grassy mountain slopes—tens of thousands of cows die because they cannot adapt to the thin, oxygen-poor air.

For the past two years, scientists collaborating with a new research facility at New Mexico State University N. Once they find the genes, the idea is to breed them out of the bovine population. From May to November each year, ranchers in many parts of the western U. In the Rockies, summer pastures range from 1, to 3, meters; an altitude greater than 1, meters is enough to induce brisket disease. In some parts of Montana and Colorado, cattle graze at altitudes upward of 4, meters, says Manny Encinias , director of N.

Whereas some cows take the swift transition to high altitudes in stride, others swell up and die. Not all breeds are equally susceptible, nor are all individuals from a single breed—just as human susceptibility to acute mountain sickness varies. Healthy cows respond to low-oxygen environments in a characteristic way: their hearts beat faster to deliver enough oxygenated blood to the body and brain, and blood vessels in the lung constrict to shunt blood to the organ's oxygen-rich areas.

Cows that develop brisket disease respond similarly, but their body's compensation is too aggressive for their own good. Blood pressure increases so much that plasma seeps out of the blood vessels into tissues surrounding the heart and lungs, bloating the cows' chests. And blood vessels in the lung constrict so much that the blood backs up into the heart, which eventually gives out. When you go from low to high altitudes, your body needs time to adjust to the change in oxygen levels.

Symptoms of high-altitude illness usually begin 12 to 24 hours after you reach a high altitude. Early symptoms include:. If you have these symptoms, stop, rest, and drink water. You may need to go back down to a lower altitude until your symptoms go away. If you have these symptoms, go to a lower altitude right away and get medical help. Symptoms that are ignored or left untreated can be life threatening.

High-altitude illness most often occurs at altitudes higher than 8, feet. Everyone is at risk for high-altitude illness. Children and older adults are at an increased risk because it takes their bodies longer to adjust. You also may be at a greater risk if you:. People who have symptoms of high-altitude illness should see a doctor. Be sure to tell him or her about the conditions you were in when you had the symptoms.

Your doctor will do a physical exam. Based on the severity of your symptoms, he or she may order tests. Tests may include a chest X-ray, brain scan, or electrocardiogram ECG.

These help diagnose the type of illness and decide on a treatment plan. The first thing you should do is to safely go down to a lower altitude right away. If your symptoms are mild, you may be able to stay at that altitude and let your body adjust. Rest and drink water until you feel better. It may help to use a device that provides extra oxygen. If needed, your doctor may prescribe medicine to prevent or treat symptoms.

One example is acetazolamide. In the UK, acetazolamide is not licensed to treat altitude sickness. But it's available from most travel clinics and some GPs may prescribe it. Begin taking acetazolamide 1 to 2 days before you start to go up in altitude and continue to take it while going up.

You should still go up gradually and follow the prevention advice, including taking time to acclimatise, having regular rest days and drinking plenty of water. If you get symptoms of altitude sickness while taking acetazolamide, rest or go down until you feel better before going up again.

Acetazolamide can be used to reduce the severity of your symptoms, but it will not completely get rid of them. Tell your travel companions how you feel, even if your symptoms are mild — there's a danger your judgement may not be clear.

After 2 to 3 days, your body should have adjusted to the altitude and your symptoms should disappear. If the symptoms of altitude sickness are ignored, they can lead to life-threatening conditions affecting the brain or lungs. A person with HACE will often not realise they're ill. They may insist they're OK and want to be left alone. Dexamethasone is a steroid medicine that reduces swelling of the brain.