An abnormal form of hemoglobin (deformed red blood cells).

A sickle- or crescent-shaped erythrocyte.

an abnormal red blood cell that has a crescent shape and an abnormal form of hemoglobin

A red blood cell that has undergone an irregular structural change, sometimes appearing like a sickle in shape. This can occur during physical and psychological stress in individuals who have a sickling hemoglobin disorder such as sickle cell anemia.

A red blood cell that has assumed an elongated shape due to the presence of hemoglobin S.

a crescent-shaped red cell characteristic of Sickle Cell Anemia