how long does altitude sickness last

Altitude sickness symptoms usually start 6 to 10 hours after reaching a high altitude (usually above 2,500 meters or 8,000 feet). The symptoms typically last about 1 to 3 days if you rest at the same altitude and allow your body to acclimate. Mild symptoms commonly include headache, loss of appetite, nausea, dizziness, fatigue, and trouble sleeping. If symptoms improve after a day or two of rest at the same altitude, it should be safe to continue ascending. However, if symptoms worsen or do not improve after one day, it is important to descend to a lower altitude by 300 to 1,000 meters to prevent more serious complications. More severe forms of altitude sickness, such as high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE), can develop within 24 to 96 hours and require immediate descent and medical treatment, as they can be life-threatening. In summary, mild altitude sickness usually resolves within a few days with rest and acclimatization, but symptoms lasting beyond this time or worsening indicate a need for descent and medical attention.