Anisocytosis vs. Poikilocytosis — What's the Difference?

Anisocytosis is a medical term meaning that a patient's red blood cells are of unequal size. This is commonly found in anemia and other blood conditions.

Poikilocytosis is variation in cell shape: poikilocytes may be oval, teardrop-shaped, sickle-shaped or irregularly contracted. Normal red blood cells are round, flattened disks that are thinner in the middle than at the edges.

(medicine) Significant size variation of blood cells

(pathology) Presence in the blood of red blood cells with abnormal shape or an entirely different shape