Head-banging is probably the most alarming of soothing techniques Baby could have picked up, but it also doesn’t generally cause any lasting harm. Babies with a preference for walls and crib-bars as head-banging surfaces can lead to a few more bumps and bruises than you’d like to see on your child, but head-banging to sleep is not generally linked to concussion or brain damage. For one thing, pain prevents babies from banging their heads too hard, and for another, they’re too young to produce the force they’d need to cause much harm even if they wanted to. In fact, head-banging often isn’t a sign of anything wrong at all.

In some cases, though, head-banging can be Baby’s way of distracting herself from a different source of pain, like an ear infection or teething, and in other rare cases it can be a sign of an underlying problem. If you’re concerned, don’t hesitate to ask Baby’s doctor to check her out. Children who head-bang and also show delays in developing communication skills, responsiveness, and imaginary play may be showing early signs of autism.

Head-banging usually starts late in the first year, around 9 months, although the rocking that sometimes goes with it can start as early as 6 months. If there is no underlying health issue behind the banging, it often goes away on its own by the time Baby is 2 and almost always by 3. The head-banging and rocking can run in families, is more common in boys than in girls, and occurs in as many as 15 to 20% of children. No one really knows why the rocking and head-banging without an underlying medical cause happens, although some experts believe it can be triggered by a change or new stress in a child’s life, or even following a large but normal milestone, like walking or starting to talk. Others think of it as an attention-seeking technique that could be a sign that a baby is not getting enough physical contact or attention.

Doctors who believe the head-banging is an attention-seeking behaviour suggest making a point to give your baby more attention during the day, when she is not head-banging, rather than rushing in to pay attention when she is, which could reinforce the behavior. Instead, redirect or distract her from headbanging with comforting techniques for bedtime, like a bath, massage, or cuddling, because making a big deal of the head-banging by saying ‘no’ could draw Baby to it more by negative reinforcement.

Waiting it out is the most well-established way of dealing with head-banging, but it can also be hard to watch as a parent. In the interest of keeping Baby from hurting herself, if you feel comfortable with it, consider moving Baby’s sleeping area to a mattress on the floor away from the wall, or a mesh-sided playpen or co-sleeper, which will keep her from finding painfully hard surfaces to head-bang against.

If you’re planning on keeping Baby in the crib throughout her head-banging phase, which many parents do, keep in mind that bumpers or pillows on the edges of the crib are still not recommended because of the suffocation risk they pose, and because determined head-bangers often find ways to get around them anyway. Do check that all of the screws and hinges on the crib are still tight and secure, though, as head-banging can loosen them and threaten some of the stability of the crib.

While head banging is often totally normal, and nothing to worry about, it's also never a bad idea to run this kind of behavior past Baby's pediatrician at a well-child visit, just so he or she has a clear idea of what's going on.