The sickle-cell and altitude.
High altitude seemed to be responsible for seven recent cases of sickling crisis. People with sickle-cell trait are at risk if they fly in unpressurized aircraft, which are used for many local air services. Those with sickle-cell haemoglobin C disease should avoid air travel even in pressurized aircraft. Possibly as a result of "autosplenectomy," patients with sickle-cell anaemia seem to be able to fly in pressurized aircraft with little risk. All passengers and aircrew who might have some form of sickle-cell disease should be screened before flight.
D000293:Adolescent; D000328:Adult; D000401:Aircraft; D000531:Altitude; D000755:Anemia, Sickle Cell / Q000150:complications / Q000209:etiology*; D001274:Atmospheric Pressure; D005260:Female; D006445:Hemoglobin C Disease; D006801:Humans; D000860:Hypoxia / Q000150:complications; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D013159:Splenic Infarction / Q000150:complications; D014195:Travel