This disease occurs in people living at an altitude of over 2500 metres.
It is characterised by low blood oxygen levels and an increase in circulating red blood cells. Those suffering from sleep apnoea or other lung diseases are more often affected, while the hormones of women of childbearing age can prevent it.
Symptoms include a bluish colouration of the skin (cyanosis), poor exercise tolerance and nervous symptoms attributed to decreased cerebral blood flow due to hyperviscosity of the blood. Symptoms may include dizziness, headaches, drowsiness, depression, tinnitus, fatigue, loss of appetite, palpitations, irritability and hallucinations.
Diagnosis is based on clinical history and a complete physical examination. Blood tests reveal oxygen deficiency, excess carbon dioxide and an increased number of red blood cells.
Treatment involves descending to sea level and, in some cases, bloodletting is used to reduce the number of red blood cells (haematocrit), thereby improving blood viscosity and alleviating symptoms of nervous origin.
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- Troy Tuttle, Asif Ali, David Filsoof, John Higgins. High altitude, air travel, and heart disease. UpToDate. Sep 08, 2015.
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