Most babies with a flat or uneven head shape can be helped with simple repositioning techniques you do at home. The skull bones in the first year of life are soft and malleable, which means the same flexibility that allowed the flattening also allows the head to round back out with consistent, gentle changes to how your baby is positioned during sleep and awake time. Visible improvement typically takes a few days to several weeks of consistent effort.
Why Baby Heads Become Flat
Babies’ skulls are made of separate bone plates connected by flexible seams called sutures. This design lets the head pass through the birth canal and accommodates rapid brain growth, but it also means external pressure can reshape the skull. When a baby spends a lot of time with the same part of the head resting against a firm surface, that area gradually flattens.
There are two common patterns. Plagiocephaly is flattening on one side of the back of the head, giving the skull a parallelogram shape when viewed from above. Brachycephaly is flattening across the entire back of the head, making it look wider and shorter. Both are caused by positional pressure, not by anything a parent did wrong. Premature babies, multiples, and babies who prefer turning their head to one side are especially prone to it.
Check for Neck Tightness First
A condition called torticollis, where the neck muscles on one side are tight and shortened, is one of the most common drivers of an uneven head shape. If your baby strongly favors looking in one direction, or their head always tilts toward the same shoulder, torticollis may be pulling them into the position that causes flattening. Correcting the head shape is much harder if the underlying neck tightness isn’t addressed at the same time.
Your pediatrician can show you gentle stretching exercises to loosen the tight side. For example, if the right side is tight, you would slowly guide your baby’s left ear toward their left shoulder while stabilizing the opposite shoulder, holding for up to 30 seconds. These stretches should be gentle and never forced. If your baby fusses or resists, stop and try again later. Pediatricians often refer families to physical therapy or an osteopathic physician for hands-on treatment that helps release the tightness. When treated early, ideally within the first month or two, torticollis often self-corrects.
Repositioning During Sleep
Babies should always be placed on their backs to sleep, for every nap and at nighttime, until they turn one. That guideline doesn’t change because of a flat spot. Side sleeping and stomach sleeping are not safe alternatives, even briefly. But you can still vary which direction your baby’s head faces while on their back.
The simplest approach: alternate which end of the crib you place your baby’s head. Babies naturally turn toward interesting stimuli like light, sound, or a parent’s voice. If the crib is against a wall, your baby will tend to look toward the room. By switching their orientation every night or every few nights, you change which side of the head bears the most pressure. You can also place yourself or a toy on the side your baby doesn’t favor to encourage them to turn that way.
Once your baby can roll both ways on their own, you can let them settle into whatever position they choose after you place them on their back. If they can only roll one direction, reposition them onto their back if they end up on their stomach.
Tummy Time Is the Most Important Tool
Every minute your baby spends on their stomach while awake is a minute with zero pressure on the back of the skull. Tummy time also strengthens the neck, shoulder, and core muscles that help your baby eventually hold their head in varied positions on their own.
You can start tummy time a day or two after birth. In the early weeks, aim for two or three short sessions a day lasting 3 to 5 minutes each. By around 2 months, the goal is 15 to 30 minutes of total tummy time spread throughout the day. As your baby gets stronger and more comfortable, sessions naturally get longer. Placing a small rolled towel under the chest, lying face-to-face with your baby, or using a play mat with colorful toys can make tummy time more enjoyable for babies who initially resist it.
Reduce Time in Containers
Car seats, bouncers, swings, and infant carriers all press against the back of the head. These devices are sometimes called “containers,” and while they’re useful and necessary in daily life, excessive time in them adds up. When your baby isn’t sleeping or traveling, try to mix in positions that take pressure off the skull: tummy time on the floor, being held upright against your chest or shoulder, or supported sitting as they get older. Even small shifts throughout the day make a difference over weeks.
Avoid Head-Shaping Pillows
You’ll find pillows, wedges, and positioners marketed to round out a baby’s head shape. The FDA warns against using these products. Infant sleep positioners and pillows pose a suffocation risk, and no product on the market has been cleared or approved by the FDA for preventing or correcting flat head shape. The risk far outweighs any potential benefit, especially since repositioning and tummy time are effective without introducing extra items into the sleep space.
When Helmet Therapy May Help
If repositioning hasn’t improved the shape enough by 4 to 5 months, or if the asymmetry is moderate to severe, your pediatrician may refer you for a cranial orthosis, commonly called a helmet. This is a lightweight, custom-fitted device your baby wears for most of the day. It works by leaving space where the skull needs to grow while gently redirecting growth away from the areas that are already prominent.
Research shows that the optimal time to start helmet therapy is around 5 to 6 months of age. Starting earlier than that often isn’t necessary because repositioning alone may still work. Starting significantly later reduces effectiveness because skull growth slows and the bones become less moldable. Most helmet treatment courses last 2 to 4 months. The helmet itself is painless, though babies need a brief adjustment period.
Signs That Need Medical Attention
The vast majority of flat head cases are positional, meaning they’re caused by external pressure and are not dangerous. In rare cases, an unusual head shape results from craniosynostosis, a condition where one or more of the skull’s sutures fuse prematurely. This restricts normal skull growth and typically requires surgical correction.
There are a few things that distinguish the two. With positional flattening, the head viewed from above looks like a parallelogram, with the ear on the flat side shifted slightly forward. With craniosynostosis, the shape tends to be more trapezoidal. A doctor checking for craniosynostosis will feel along the suture lines for hard ridges where bone has fused and check whether the soft spot on top of the head feels normal. If your baby’s head shape seems to be getting worse despite consistent repositioning, or if you feel a raised ridge along any of the skull seams, bring it up with your pediatrician.
What to Realistically Expect
Most positional flattening improves noticeably once you begin consistent repositioning and increase tummy time. Some parents see changes within days, though it more commonly takes several weeks to see a visible difference. The younger your baby is when you start, the faster results tend to come, simply because the skull is growing rapidly and is at its most flexible. By the time babies are sitting up, crawling, and spending less time on their backs, the natural reduction in pressure on the skull helps the process along considerably. Most children’s heads round out well before their second birthday, and mild residual asymmetry is common and typically hidden once hair grows in.