[Skip to Content]

Flat Head Syndrome (Positional Plagiocephaly)


What Is Flat Head Syndrome?

Flat head syndrome usually happens when a baby sleeps in the same position most of the time or because of problems with the neck muscles. This causes a flat spot, either on one side or the back of the head.

Flat head syndrome is also called positional plagiocephaly (pu-ZI-shu-nul play-jee-oh-SEF-uh-lee).

What Causes Flat Head Syndrome?

The most common cause of a flattened head is a baby's sleep position. Infants are on their backs for so many hours every day, so the head sometimes flattens in one spot. This happens not only while they sleep, but also from being in infant car seats, carriers, strollers, swings, and bouncy seats.

Premature babies are more likely to have a flattened head. Their skulls are softer than those of full-term babies. They also spend a lot of time on their backs without being moved or picked up because of their medical needs, such as a stay in the neonatal intensive care unit (NICU).

Flat head syndrome can even start before birth if there's pressure on the baby's skull from the mother's pelvis or a twin. In fact, many babies from multiple births are born with heads that have some flat spots.

Being cramped in the womb can also cause torticollis, which can lead to a flattened head. Babies with torticollis have a hard time turning their heads because of tight neck muscles on one side of the neck. Because it's hard to turn their head, they tend to keep their heads in the same position when lying down. This can cause flattening.

Likewise, many babies who started out with flat head syndrome develop torticollis. It takes a lot of energy for babies to turn their heads. So those with severe flattening on one side tend to stay on that side, and their necks become stiff from lack of use.

What Are the Signs & Symptoms of Flat Head Syndrome?

Flattened head syndrome usually is easy for parents to notice:

  • The back of the baby's head is flatter on one side.
  • The baby usually has less hair on that part of the head.
  • When looking down at the baby's head, the ear on the flattened side may look pushed forward.

In severe cases, the head might bulge on the side opposite from the flattening, and the forehead may be uneven. If torticollis is the cause, the neck, jaw, and face might be uneven as well.

How Is Flat Head Syndrome Diagnosed?

Doctors often can diagnose flat head syndrome by looking at the baby's head. To check for torticollis, the doctor may watch how a baby moves the head and neck. Medical tests usually are not needed.

How Is Flat Head Syndrome Treated?

Caregivers should always place babies on their back to sleep to help prevent sudden infant death syndrome (SIDS), even with possibility of flat head syndrome.

So what can parents do when flat head syndrome is due to a sleeping or lying position? Simple practices like changing a baby's sleep position, holding your baby, and providing lots of "tummy time" can help it go away. Try these tips:

  • Change the head position while your baby sleeps. Change the position of your baby's head (from left to right, right to left) when your baby is sleeping on the back. Even if your baby moves around during the night, place your child with the rounded side of the head touching the mattress and the flattened side facing up. Don't use wedge pillows or other devices to keep your baby in one position.
  • Vary positions in the crib. Consider how you lay your baby down in the crib. Most right-handed parents carry infants cradled in their left arms and lay them down with the heads to their left. In this position, the infant must turn to the right to look out into the room. Position your baby in the crib to encourage active turning of the head to the side that's not flattened.
  • Hold your baby more often. Limit the time your child spends lying on the back or with the head resting against a flat surface (such as in car seats, strollers, swings, bouncy seats, and play yards). For instance, if your baby has fallen asleep in a car seat, take your baby out of the seat when you get home rather than leaving your little one snoozing in the seat. Pick up and hold your baby often, which will take pressure off the head.
  • Practice tummy time. Provide plenty of supervised time for your baby to lie on the stomach while awake during the day. Tummy time:
    • helps normal shaping of the back the head
    • encourages a baby's learning and discovery of the world
    • helps babies strengthen their neck muscles and learn to push up on their arms, which helps develop the muscles needed for crawling and sitting up

Most babies with flat head syndrome also have some degree of torticollis. So physical therapy and a home exercise program usually are part of treatment. A physical therapist can teach you exercises to do with your baby involving stretching. Most moves involve stretching the neck to the side opposite the tilt. In time, the neck muscles will get longer and the neck will straighten itself out. The exercises are simple, but must be done correctly.

If repositioning for 2–3 months doesn't help a child with severe flat head syndrome, doctors may prescribe a custom-molded helmet or headband. While helmets might not work for all children, they can help some kids with severe torticollis.

The helmets work best if used between the ages of 4–12 months, when a child grows the fastest and the bones are most moldable. They work by applying gentle but constant pressure on a baby's growing skull to redirect the growth.

Never use any devices like these without first having your child seen by a doctor. Only a very few babies wear helmets (for example, if the condition is so severe that a baby's face is becoming misshapen).

What Else Should I Know?

Flat head syndrome doesn't affect a baby's brain development or cause any lasting appearance problems. As babies grow, they begin to change position themselves during sleep, so their heads aren't in the same position.

When an infant can sit on his or her own, a flat spot usually won't get any worse. Then, over months and years, as the skull grows, the flattening will improve, even in severe cases.