Head-banging against a pillow is pretty harmless, says Dr. Dmitriy...

Head-banging against a pillow is pretty harmless, says Dr. Dmitriy Vaysman, and children usually outgrow it by age 3 or 4. Credit: Depositphotos / Ozgur Coskun

Q. While trying to fall asleep and when sleeping, sometimes my 2-year-old bangs his head repeatedly on his pillow. It doesn’t wake him up, but it’s freaking me out. Why does he do this, and should I be worried?

A. Nocturnal head-banging happens in otherwise healthy children, says Dr. Dmitriy Vaysman, director of pediatric pulmonology and sleep medicine at Good Samaritan Medical Center in West Islip. It’s an involuntary motion that the child makes unconsciously, he says.

The head-banging falls under the category of rhythmic movement disorders, Vaysman says. But that designation sounds worse than it is, and it can be more disconcerting for the parent than it is for the child. “They’re usually banging their head against something cushioned,” Vaysman says. “They usually don’t hurt themselves.” It isn’t worth trying to tell your child to stop, because he probably doesn’t even realize he is doing it and wouldn’t be able to control it while sleeping, anyway, he says.

The head-banging typically starts during the toddler age, Vaysman says. “When does it stop? Everybody’s different,” he says. “If it’s a developmentally normal child, it usually goes away over time. Most kids outgrow it by 3 or 4 years of age.” As for why some kids do this, “I don’t think anybody truly knows,” Vaysman says.

If your child is banging his head so frequently or vigorously that you’re really worried, you could bring the child to a neurologist to make sure he doesn’t have a seizure disorder, Vaysman says. But usually, “it’s a self-limiting problem,” he says.