The Air Up There: How To Avoid Altitude Sickness

Authored by Dr. Jeff Bennert

When a person travels to a location that is greater than 8,000 feet, they must do so at a speed that allows their body to acclimatize to certain changes, such as decreased air pressure, low humidity, and greater exposure to ultraviolet rays. Typically, full acclimatization can take as much as five days. If a person does not fully acclimatize to the higher altitude, it may cause a condition known as altitude sickness. The three forms of altitude sickness are acute mountain sickness, high altitude pulmonary edema, and high-altitude cerebral edema. Many people enjoy activities that allow them to get outside and take in some fresh air, but hikers, skiers, and others who are traveling to great heights must educate themselves about altitude sickness when planning their trip. This knowledge is important so that they can prevent or recognize it, and know what to do if they or one of their companions should become ill.

People hiking or otherwise traveling to higher altitudes can take steps to help them adjust more efficiently. This includes being well rested prior to the trip, ascending at a gradual pace, including rest days, and giving the body time to adjust to being at the new altitude. Alcohol and tobacco use should also be avoided in efforts to prevent the onset of the illness. People should be wary of taking medications that claim to prevent altitude sickness from occurring. Currently, only acetazolamide is known to help speed up the rate that one acclimatizes to higher altitudes; however, studies have shown that ibuprofen may also be helpful. When planning a camping or hiking trip that involves traveling to a higher altitude, one should visit their family physician, who can discuss acetazolamide and its potential side-effects, which may include tingling of fingers.

The most common altitude sickness is acute or mild mountain sickness. Symptoms of this sickness typically begin as early as two hours after reaching the higher altitude, or as long as 12 hours after. The symptoms that are associated with this condition include headache, nausea, and a loss of appetite. Additional symptoms may also include feelings of weakness, vomiting, and swelling of one’s extremities. Altitude sickness that involves a build-up of fluid in the brain is known as high-altitude cerebral edema (HACE). This condition is more advanced and life-threatening than acute mountain sickness. When a person develops HACE they must return to their normal altitude immediately and seek medical attention. HACE symptoms are the same as the symptoms of acute mountain sickness; however, suffers will also experience extreme lethargy, confusion, drowsiness, and ataxia. Although this is a rare form of altitude sickness, it should be taken very seriously, as failure to descend can lead to death within 24 hours. When fluid builds up in the lungs due to poor acclimatization at high altitudes, it is known as high altitude pulmonary edema. A person with high-altitude pulmonary edema, or HAPE, may or may not also suffer from HACE or acute mountain sickness. Like HACE, this condition is life-threatening and requires immediate descent as death can occur even more quickly. People who are suffering from HAPE will experience feelings of increased breathlessness and may show signs of blue fingernails or lips. Initially, this will occur with exertion, however as it worsens the individual will also experience extreme breathlessness at rest, and also coughing and weakness.

Treatment depends on the type of altitude sickness that the person is suffering from. When dealing with acute mountain sickness, the mildest form of altitude sickness, a person can wait for their body to adjust, provided symptoms do not progress. If symptoms worsen or if a person is suffering from HAPE or HACE, descent should begin immediately. Descend until symptoms begin to fade, which is often around 1,500 to 2,000 feet for moderate symptoms. When symptoms are moderate, improvement will take place within 24 hours. Continue down further, below 4,000 feet, if symptoms are more severe. While descending, the person suffering the symptoms should try to minimize any exertion and should also be given fresh air in the form of oxygen if it is available. Efforts should also be made to keep the person hydrated, well rested and warm. Ibuprofen may be given to treat the head pain; however, if the symptoms are severe or do not resolve, it is important to seek medical attention right away. Treatment for fluid in the lungs includes oxygen, as previously noted, a lung inhaler, and, in severe cases, a respirator. People with cerebral edema, or fluid on the brain, are given a steroid called dexamethasone to reduce the swelling and other symptoms. Once improved, there are typically no side-effects associated with mild or medium level symptoms.

Traveling to high altitudes has many benefits for people who enjoy the outdoors. Activities such as camping, skiing, snowboarding, and hiking allow people to take in and enjoy all of the beauty that can be found at these heights. Unfortunately, altitude sickness is a common problem, particularly when someone is unfamiliar with traveling to higher altitudes or if they have had the illness previously. Because it is potentially a deadly condition, it is crucial that travelers educate themselves on all aspects of the condition, particularly how to identify and treat it.