If a child complains of cramping, achy muscle pains in their arms and legs at night, they are probably suffering from growing pains.

As many as a third of all pre-school and primary school-age children are affected, according to experts in Germany.

Growing pains don’t occur during physical activity, but rather in periods of rest – usually at night. They mainly affect the calves, the back of the knees, the shins and the thighs. The joints aren’t affected. In the morning, the pain is typically gone, and the child can get up and walk normally.

Doctors aren’t exactly sure what causes growing pains. One theory is that growth causes tension in the periosteum, a dense layer of vascular connective tissue enveloping the bones. Another possibility is that the bones become fatigued during growth.

While there’s no specific treatment for growing pains, sometimes massages, a hot-water bottle or a cooling pack can bring relief, according to the Berlin-based Professional Association of Orthopaedics and Traumatology. In rare cases, a doctor can prescribe pain medication.

If a child complains of persistent pain, parents should consult a doctor. Besides growth, aching legs and arms can also be caused by a serious illness such as rheumatism or an undetected bone fracture. – dpa