Does Craniosynostosis Cause Pain or Headaches in Infants?

A common and understandable fear for parents is whether their baby’s fused skull is causing them day-to-day pain before surgery. The short answer is that the fused bone itself does not typically cause localized pain ^[1][2]. While waiting for surgery, your baby will likely eat, sleep, and play just like any other infant.

However, if the premature fusion prevents the skull from expanding enough to accommodate the rapidly growing brain, it can eventually lead to elevated intracranial pressure (a build-up of pressure inside the skull) ^[3]. While this sounds frightening, it is important to know that in the most common form of the condition (isolated single-suture craniosynostosis), elevated pressure is relatively rare in infants younger than 6 months old ^[4][5]. The risk increases gradually as the baby grows older, giving your medical team time to monitor and intervene before pressure becomes dangerous ^[4].

Understanding Intracranial Pressure (ICP)

The skull normally expands as a baby’s brain grows. Because craniosynostosis involves premature fusion of one or more cranial sutures, the skull may not be able to expand properly. This creates a mismatch between the size of the growing brain and the limited space available inside the skull, which elevates the pressure of the fluid and tissue inside ^[3]. When pressure builds up, it can cause significant discomfort, headaches, and other symptoms ^[6].

The risk of elevated pressure depends heavily on the baby’s age and the specific diagnosis. Ask your medical team which type of craniosynostosis your baby has, as this affects their risk:

• Single-suture craniosynostosis: Only one seam in the skull has fused early. The risk of elevated pressure is lower and typically develops gradually over months ^[4].
• Syndromic or multi-suture craniosynostosis: Multiple seams are fused, or the condition is tied to a broader genetic syndrome. The risk of elevated pressure is significantly higher in these cases ^[7][8].

Signs of Elevated Pressure in Babies

Because infants cannot tell you if they have a headache or feel nauseated ^[6], parents must look for physical and behavioral clues. Symptoms can be treated and often improve significantly after surgical procedures that expand the skull and relieve the pressure ^[9][10].

If you notice any of the following signs, you should contact your child’s medical team immediately. While pressure usually builds gradually, these signs indicate that the pressure needs evaluation:

• A bulging fontanelle: The “soft spot” on top of the head feeling tense, firm, or bulging outward when the baby is sitting upright and calm ^[6].
• Extreme irritability: A high-pitched cry, or being unusually fussy and impossible to soothe for extended periods ^[6].
• Lethargy: Being excessively sleepy, unusually difficult to wake up, or showing a sudden, significant lack of interest in feeding ^[6].
• Projectile vomiting: Forceful vomiting that is unusual for your baby and not just normal spit-up ^[6].
• “Sunsetting” eyes: A downward gaze where the white part of the eye persistently shows above the colored iris, making the eyes look like a setting sun ^[11][12].

How Doctors Monitor for Pressure

Your medical team will monitor your baby closely before surgery to ensure they are comfortable and safe. They may look for physical signs or use non-invasive tests to evaluate the pressure around the brain.

• Eye and vision exams: Doctors may look into the back of the baby’s eyes for papilledema (swelling of the optic nerve caused by pressure) ^[6]. Because traditional exams can be difficult to perform on moving babies and can sometimes miss early swelling, specialists frequently use advanced, non-invasive tools like ultrasound or optical coherence tomography (OCT) to measure the optic nerve safely ^[13][14][15]. Doctors may also use Visual Evoked Potentials (VEP) tests, which involve placing harmless sensors on the scalp to measure how well the brain processes visual information ^[16].
• Skull Imaging: X-rays or CT scans might show a pattern on the inside of the skull that radiologists call a “beaten copper” appearance or thinning of the bone ^[17][18]. This is simply a visual medical term for how the bone looks on the scan—it does not mean the skull is actually damaged like metal. It just indicates that the growing brain has been pressing against the inner bone over time.