Microcephaly means a baby’s head is much smaller than expected for age and sex. The difference is usually clear at birth or shows up during the first two years of life.

The most visible sign is the head size itself. When measured, the distance around the skull falls below the third percentile on standard growth charts.

A small head can make the face look larger and the back of the head flatter. Fontanelles—the soft spots—may close early, and forehead slope can seem pronounced.

Development often slows. Sitting, crawling, or walking may arrive late. Some children need extra help with speech or hand skills.

Muscle tone can swing either way. Babies may feel floppy when picked up, or stiff and hard to cuddle later.

Feeding issues are common. Weak suck, frequent gagging, or reflux can slow weight gain.

Seizures may appear in the first months. They can be brief staring spells or full-body jerks noticeable even to new parents.

Vision and hearing can be off. A child might not track toys or react to sounds, leading to repeat hearing tests or eye checks.

Balance and coordination vary. Some kids walk with a wide, unsteady gait and need helmets to protect the smaller skull from bumps.