As disc-shaped erythrocytes pass through capillaries, which can be 2–3 micrometres wide, they are forced to assume an elliptical shape in order to fit through.

These elliptical cells are taken up by the spleen and removed from circulation when they are younger than they would normally be, meaning that the erythrocytes of people with hereditary elliptocytosis have a shorter than average life-span (a normal person's erythrocytes average 120 days or more).Inheritance of multiple mutations tends to infer more serious disease.

The diagnosis of hereditary elliptocytosis is usually made by coupling a family history of the condition with an appropriate clinical presentation and confirmation on a blood smear.

[citation needed] Because the spleen breaks down old and worn-out blood cells, those individuals with more severe forms of hereditary elliptocytosis can have splenomegaly.

Because many neonates with severe elliptocytosis progress to have only a mild disease, and because this age group is particularly susceptible to pneumococcal infections, a splenectomy is only performed on those under 5 years old when it is absolutely necessary.

[citation needed] Those with hereditary elliptocytosis have a good prognosis, only those with very severe disease have a shortened life expectancy.

[citation needed] The incidence of hereditary elliptocytosis is hard to determine, as many sufferers of the milder forms of the disorder are asymptomatic and their condition never comes to medical attention.

A clinically significant haemolytic anaemia occurs only in 5-10% of sufferers, with a strong bias towards those with more severe subtypes of the disorder.