The suggested rate of ascent is the same that applies to the prevention of acute mountain sickness and high-altitude cerebral edema. The Wilderness Medical Society (WMS) recommends that, above 3,000 metres (9,800 ft), climbers

not increase the sleeping elevation by more than 500 metres (1,600 ft) a day, and
include a rest day every 3–4 days (i.e., no additional ascent).In the event that adherence to these recommendations is limited by terrain or logistical factors, the WMS recommends rest days either before or after days with large gains. Overall, WMS recommends that the average ascent rate of the entire trip be less than 500 metres (1,600 ft) per day.The most studied and preferred medication for prevention of HAPE is nifedipine, a pulmonary vasodilator which prevents the altitude induced pulmonary hypertension. The recommendation for its use is strongest for individuals with a history of HAPE. According to published data, treatment is most effective if given one day prior to ascent and continued for four to five days, or until descent below 2,500 meters (8,200 ft).Additional medications that are being considered for prevention but require further research to determine efficacy and treatment guidelines include acetazolamide, salmeterol, tadalafil (and other PDE5 inhibitors), and dexamethasone. Acetazolamide has proven to be clinically effective, but formal studies are lacking. Salmeterol is considered an adjunctive therapy to nifedipine, though only in highly susceptible climbers with clearly demonstrated recurrence of HAPE. Tadalafil was found to be effective at preventing HAPE in HAPE-s individuals during rapid ascent, but optimal dosing and frequency has yet to be established.
This is evidenced by the appearance of "diffuse," "fluffy," and "patchy" infiltrates described on imaging studies of climbers with known HAPE.Although higher pulmonary arterial pressures are associated with the development of HAPE, the presence of pulmonary hypertension may not in itself be sufficient to explain the development of edema; severe pulmonary hypertension can exist in the absence of clinical HAPE in subjects at high altitude. Diagnosis
The diagnosis of HAPE is entirely based on symptoms and many of the symptoms overlap with other diagnoses. Before HAPE was understood it was commonly confused with pneumonia which resulted in inappropriate treatment.HAPE generally develops in the first 2 to 4 days of hiking at altitudes >2,500 meters (8,200 ft), and symptoms seem to worsen most commonly on the second night. Initial symptoms are vague and include shortness of breath, decreased exercise ability, increased recovery time, fatigue, and weakness, especially with walking uphill. People then develop a dry, persistent cough, and often cyanosis of the lips. Another cardinal feature of HAPE is the rapid progression to dyspnea at rest. The development of pink, frothy, or frankly bloody sputum are late features of HAPE. In some cases, people will develop concomitant neurological features such as poor coordination, altered consciousness, or cerebral edema (High-altitude cerebral edema).On physical exam, increased breathing rates, increased heart rates, and a low-grade fever 38.5o (101.3o F) are common. Listening to the lungs may reveal crackles in one or both lungs, often starting in the right middle lobe.