Altitude sickness is caused by reduced oxygen and barometric pressure at altitudes above 8,000 feet (2,438 meters). For detailed information on signs, symptoms, and treatment, go to the Centers for Disease Control (CDC) or WebMD. (In addition, the Mayo Clinic has an article about airplane ear, also known as ear barotrauma, which is more a type of decompression sickness.)
Types of Altitude Sickness
There are 3 basic types of altitude sickness:
- Mild altitude sickness (sometimes called acute mountain sickness or AMS)
- High-altitude pulmonary edema (HAPE)
- High-altitude cerebral edema (HACE)
Acute mountain sickness (AMS)
Individuals experiencing AMS have symptoms similar to a hangover: headache, nausea, and fatigue. Some individuals may not be affected at all by AMS, while others are only slightly affected or feel awful. Any adverse effects of being at a high altitude should be taken as a warning sign to stop all activity and seek treatment to prevent more serious forms of altitude sickness from developing.
High-altitude pulmonary edema (HAPE)
HAPE is a more serious form of altitude sickness characterized by excess fluid in the lungs. This can be fatal especially in a low-oxygen environment. The major sign of HAPE is breathlessness even when the patient is at rest. Breathlessness at rest is never normal—not even at high altitude. HAPE may also result in a fever, coughing with a frothy discharge, and progressively more difficulty breathing.
Note: A condition known as high altitude cough may be present without HAPE. This is a dry, debilitating cough that can be so severe that it can disturb sleep and even cause physical damage to the patient. If an individual is experiencing a cough mixed with breathlessness, this may indicate HAPE.
High-altitude cerebral edema (HACE)
HACE is a perhaps the most serious form of altitude sickness characterized by excess fluid on the brain. HACE may begin with uncharacteristic behavior such as extreme emotions, lethargy, or violence. As the condition advances, it causes clumsiness, confusion, drowsiness, and eventually loss of consciousness. HAPE and HACE can occur at the same time.
Care for Altitude Sickness
To care for altitude sickness:
- Have the patient stop all activity and rest.
- Determine the seriousness of the condition. If the patient is out of breath even though at rest or unusually confused or drowsy, make arrangements to move the patient to a lower altitude as soon as possible.
- Monitor vital signs and be prepared to provide ventilations or CPR, if necessary.
- Administer emergency oxygen, if available.
- Care for shock by maintaining the patient’s normal body temperature and remaining with the patient for comfort and reassurance.