Flat head syndrome

Also called Plagiocephaly or Brachycephaly

Flat head syndrome is when a baby's head has a flat spot at the back or on one side. Babies' skulls are soft, so lying in the same position for long periods can change the shape. It is common, does not affect the brain, and usually gets better as the baby grows and moves more.

Last updated Nov 9, 2026

What it is

Babies should still always sleep on their backs. Tummy time while awake and changing the position of the head help.

Helmets are rarely needed and their benefit is unclear.

Common signs

  • A flat area at the back or on one side of the head
  • One ear or side of the face slightly further forward
  • A wider head shape

How it is usually diagnosed

  • Examination of the head shape by a doctor or health visitor

Records worth keeping

Keeping these together makes each appointment easier, especially when you see a new doctor:

  • Health visitor or paediatric notes
  • Head shape measurements or photos over time

Questions to ask your doctor

  • Is this flat head syndrome or something else?
  • What positions should I try?
  • When should it improve?

When to get help right away

Call 112 or go to the nearest emergency department if you have:

  • A soft spot on the head that bulges, with vomiting, drowsiness or a fever: call 112

This page is general information. It is not a diagnosis and does not replace a doctor who knows your history. Medfold keeps your records organised; it does not interpret them.

Sources