After ascent to high altitude (≥2500 m), the inability of the human body to adapt to the hypobaric and hypoxia environment can induce tissue hypoxia, then a series of high altitude illnesses including acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE) would develop. Symptoms of AMS include headache, dizziness, nausea, and vomiting; HAPE is characterized by orthopnea, breathlessness at rest, cough, pink frothy sputum, and results in obvious pulmonary edema that poses significant harm to people; HACE is characterized by ataxia and decreased consciousness, leading to coma and brain herniation which would be fatal if not treated promptly. This review article provides a current understanding of the pathophysiology of these three forms of high altitude illness and elaborates the current prevention and treatment measures of these diseases. •AHAI refers to a series of syndromes including AMS, HAPE and HACE.•HAPE is related with hypoxic pulmonary hypertension and alveolar fluid clearance.•AMS and HACE is related with cerebral hemodynamics and cytokines variation.•Current chemical drugs used to prevent AHAI have obvious toxic side effects.•Foodborne natural substances should be developed to prevent against AHAI.