<unk>  <unk>  is a disease in which the proportion of blood volume that is occupied by red blood cells increases (polycythaemia) and there is an abnormally low level of oxygen in the blood (hypoxemia).<unk>  typically develops after extended time living at high altitude (over ). It is most common amongst native populations of high altitude nations. The most frequent symptoms of<unk>  are headache, dizziness, tinnitus, breathlessness, palpitations, sleep disturbance, fatigue, loss of appetite, confusion, cyanosis, and dilation of veins.<unk>  was first described in 1925 by Carlos Monge Medrano, a Peruvian doctor who specialised in diseases of high altitude. While acute<unk>  sickness is experienced shortly after ascent to high altitude,<unk>  may develop only after many years of living at high altitude. In medicine, high altitude is defined as over , but most cases of<unk>  occur at over . It has recently been correlated with increased expression of the genes ANP32D and SENP1.
Chronic mountain sickness
Decompression sickness
Ski sickness
Motion sickness
Simulator sickness
Altitude sickness
Morning sickness
Sweating sickness