Nighttime leg pain in kids is fairly common, especially between the ages of 3 to 12 years. In many cases, it is due to growing pains, but other causes should not be ignored. Here's a detailed explanation: Common Causes of Leg Pain at Night in Kids 1. Growing Pains Most common cause; linked to muscle fatigue and growth spurts. Symptoms: Dull, aching pain in both legs (usually calves, thighs, or behind knees), often at night. Pain disappears by morning. No swelling or redness. 2. Muscle Fatigue Du