What types of semen anatomical abnormalities exist?

Potential defects or anomalies that can be found in sperm include:

Head defects

too small, too large, double-headed, balloon-shaped, with too large vacuoles...

Midpiece defects

too thin, too thick, too short, too long, bent, without neck...

Tail defects

too short, too long, duplicate tails, coiled, detached tail...

A single spermatozoon can have just one anomaly or, conversely, multiple defects.

In any case, with just an abnormality in one part, the sperm cell is considered an abnormal one.