User:Mr. Ibrahem/High-altitude pulmonary edema

High-altitude pulmonary edema
Other names	High-altitude pulmonary oedema (HAPO)
Chest x-ray of HAPE showing characteristic patchy alveolar infiltrates with right middle lobe predominance.
Specialty	Emergency medicine, wilderness medicine
Symptoms	Shortness of breath, bluish colored skin, cough
Usual onset	2 to 5 days
Causes	Altitude > 2,500 meters (8,200 ft)
Diagnostic method	Based on symptoms
Differential diagnosis	Asthma, acute bronchitis, pneumonia, heart attack
Treatment	Immediate descend, oxygen, nifedipine, portable hyperbaric chamber
Frequency	At 4,500 meters (15,000 ft) ~3%

High-altitude pulmonary edema (HAPE) is a type of altitude illness were fluid builds up in the lungs. Early symptoms may include tiredness, shortness or 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 2,500 meters (8,200 ft) but may occur as low as 2,000 meters (6,600 ft). 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 4,500 meters (15,000 ft) 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.