Altitude sickness

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at May 30, 2016
StartDiseasesAltitude sickness

When a person that isn’t used to high altitudes moves to an elevation of 8,000 feet or more, then it can lead to altitude sickness. While mild altitude sickness is normal and typically only causes discomfort, more severe forms of it do exist. If the sickness progresses into a more acute form, then it can lead to severe symptoms, incapacitation, and even death. Altitude sickness is sometimes called mountain sickness, and it usually occurs when a person travels a certain distance above sea level.


Definition & Facts

In some cases, a person may suffer from altitude sickness going as low as 4,800 feet. No matter the elevation, mountainous regions are commonly associated with altitude sickness because people travel to them for recreation.

Bikers, skiers, mountain climbers, and hikers are all at risk, as are visitors to places like Colorado or Nepal. Altitude sickness may result in complications such as high-altitude pulmonary edema or high-altitude cerebral edema, and both can become lethal.

Symptoms & Complaints 

People who have suffered from altitude sickness have compared it to a hangover. A throbbing headache is one of the common symptoms, but it can also include nausea, vomiting, weakness, dizziness, or a loss of appetite.

The severity of those symptoms varies, along with the period of sickness. In some cases, the problems won't begin until after a day of staying or traveling at a high altitude. Though it may only be a mild condition, altitude sickness can affect the lungs and brain. If it does, additional symptoms include:

In some cases, those suffering from altitude sickness might hear a sound like a crumpling paper bag while breathing. If so, then it means the sickness has gone from mild to severe and that high-altitude pulmonary edema has afflicted a person. This involves the buildup of fluid in the lungs which in turn can lead to respiratory failure, a lethal condition.

Alternatively, the buildup of fluid in the brain means that the sickness has progressed into high-altitude cerebral enema. It affects a person’s mental state with symptoms such as loss of coordination and can result in coma and death.


Altitude sickness is commonly triggered when a person’s rate of ascent happens too fast for the body to adjust because the level of oxygen in the air decreases as the altitude increases. Altitude sickness happens not only when a person’s elevation exceeds 8,000 feet, but also when the rate of ascent goes past 1,000 feet a day. Low blood levels of oxygen that follow can contribute. Several factors might lead to sickness, including:

Some people are less susceptible to having altitude sickness than others. Conversely, those who live at an altitude of 3,000 feet or below have a higher risk of having altitude sickness. The same applies to those below the age of 50, or who have experienced altitude sickness in the past.

Diagnosis & Tests 

Making a diagnosis for altitude sickness depends on the symptoms displayed as well as the travel history of the afflicted. There are no specific tests that diagnose the sickness. However, a doctor can still be recruited to assess the person’s condition. Emergency medicine physicians, neurologists, and critical care specialists are all viable, depending on the severity.

No matter the type, the doctor will typically gauge the status of the patient through listening and observation. Checking the patient’s respiratory functions is common, which involves checking the patient for shortness of breath or listening to the lungs for rattling sounds.

Vital signs are checked in kind, in case of a fever or abnormal heart rate. Heart palpitations may be evidence of high-altitude pulmonary edema. If the patient appears to be suffering from high-altitude pulmonary edema, the doctor may conduct a chest X-ray to confirm its presence. A diagnosis of high-altitude cerebral edema may be made based on observation of a person's behavior as well as imaging studies such as CT scans and MRIs.

Treatment & Therapy 

Those that suffer from mild altitude sickness can stay at that altitude and wait for their bodies to get used to the environment. Still, staying at the current altitude is only possible if the afflicted rest, limit physical activity, drink water, and don’t go any higher. While the process can take anywhere from 12 hours to 4 days, it can help ensure a safe recovery.

If that doesn’t work, or if the sickness is too extreme, then one of the best treatments is to simply go to an altitude at least 1,500 feet lower. This is recommended for people whose symptoms are at least moderate, worsen over time, or remain unaffected by medicine. Individual symptoms can also be treated with over-the-counter medicines, particularly for headaches or stomach aches.

In extreme situations, oxygen can be supplied to people with altitude sickness. Alternatively, a portable hyperbaric chamber can simulate the effect of a lower altitude, especially if it becomes impossible to travel any further downward.

Prevention & Prophylaxis

Preventing altitude sickness is possible by preparing in advance. People that want to go on a high-altitude trip should start by spending time at a medium-altitude location first, so the body can begin acclimating to the area. Rest and hydration beforehand help as well, along with eating carbohydrate-rich foods like bread or pasta.

Special medications are available as long as doctors recommend them first. Taking ibuprofen before and during a high elevation climb has been shown to reduce or even prevent altitude sickness. Similarly, acetazolamide helps the body adapt to altitudes faster.