What does haemolysis mean?
Haemolysis is the rupture and destruction of red blood cells, with haemoglobin released from their interior into the surrounding fluid. The process can occur within the circulation, known as intravascular haemolysis, or when cells are removed or damaged elsewhere, especially in the spleen, known as extravascular haemolysis. In medicine, the word commonly appears in discussions of haemolytic anaemia, blood transfusions, haemolytic disease of the newborn, and laboratory samples affected by fragile cells. Although haemolysis is often identified as a laboratory sign, extensive haemolysis can impair the blood's ability to carry oxygen and may require urgent assessment. The term is technical and chiefly British in spelling, while hemolysis is standard in American usage. Haemolytic is the usual adjective, as in a haemolytic reaction, and haemolysin names a substance capable of causing the process.
nounThe rupture or destruction of red blood cells, with the release of their haemoglobin into the surrounding fluid, especially blood plasma.
- The rupture or destruction of red blood cells, resulting in the release of haemoglobin into the blood plasma or another surrounding fluid.
"The blood sample showed evidence of haemolysis, so the laboratory repeated the test with a fresh specimen."
"Incompatible red blood cells can trigger haemolysis after a transfusion."
"Haemolysis in the sample made the haemoglobin measurement unreliable, so the specimen was collected again."
Haemolysis is normally treated as an uncountable noun naming a process, so it is used without a plural form.
"The test detected haemolysis in the blood sample."
When red blood cells rupture, they spill their haemoglobin into the surrounding fluid—a laboratory clue that can point to serious disease.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does haemolysis come from?
The word was formed in New Latin from Greek haîma, “blood”, and lysis, “a loosening”. In medical usage, lysis denotes the disruption or dissolution of cells, while the combining form haem- means blood. Related English words include haematology, haemoglobin and haemophilia, all of which reflect the same Greek root for blood.
Related word forms
How haemolysis is actually used
This is a technical medical and biological term. It is especially common in haematology, transfusion medicine and laboratory diagnosis. Haemolytic is the usual adjective, while haemolysis is chiefly the British spelling and hemolysis is standard in American usage.