Haematology & OncologyPending review
Sickle Cell Disease
An inherited haemoglobinopathy in which abnormal haemoglobin S polymerises when deoxygenated, distorting red cells into rigid sickles that occlude small vessels and haemolyse, so hypoxia, dehydration, cold and infection all precipitate the same vaso-occlusive crisis.
In a nutshell
HbS polymerises when deoxygenated, distorting red cells into rigid sickles that both block small vessels (vaso-occlusion) and lyse prematurely (haemolysis). Hypoxia, dehydration, cold and infection all push more haemoglobin toward polymerisation, explaining the recognised crisis triggers.
Classic presentation
A patient with known sickle cell disease develops severe acute bone pain during an episode of dehydration, cold exposure or infection, on a background of chronic haemolytic anaemia.
Key points
- Sickling is triggered by deoxygenation, so hypoxia, dehydration, cold and acidosis are the classic precipitants of a crisis.
Educational content pending clinical review. Not medical advice.