User:Mr. Ibrahem/High-altitude pulmonary edema

High-altitude pulmonary edema (HAPE) is a type of altitude illness were fluid builds up in the lungs. Early symptoms may include tiredness, shortness of breath with exercise, and dry cough. This may worsen to shortness of breath at rest, pink tinged cough, and bluish colored skin. Onset is generally after being at altitude for 2 to 5 days. About 15% of cases are complicated by high altitude cerebral edema.

It mostly occur due to altitudes above 2500 m but may occur as low as 2000 m. Risk factors include genetics, rapid ascent, strenuous exercise, pulmonary hypertension, and a high salt diet. The underlying mechanism is believed to involve constriction of blood vessels in the lungs as a response to low oxygen. It is a type of noncardiogenic pulmonary edema. Diagnosis is based on symptoms.

Treatment is by immediate descend to a lower altitude. If descending is not possible oxygen, nifedipine, or a portable hyperbaric chamber may be used. At 4500 m about 0.6 to 6% of people are affected. Males are more commonly affected than females. Severe cases may have a risk of death of up to 50% without treatment.