Growing Pains or Something Else? Leg Pain in Children

Growing pains are muscle aches in both legs, usually the thighs, calves, or behind the knees, that arrive in the evening or wake a child from sleep and are gone by morning. They never cause fever, swelling, or a limp. Leg pain that stays in one spot, sits inside a joint, hurts in the morning, or comes with fever, a limp, or refusal to walk is something else and needs a doctor. Here is how to tell the two apart.

What Growing Pains Actually Feel Like

Growing pains have a recognizable shape, and the shape matters more than how loudly your child cries. The ache sits in the muscle: the front of the thighs, the calves, or behind the knees. It is usually in both legs, it starts at bedtime or a few hours into sleep, and it is gone by morning. The child who was inconsolable at 10 p.m. runs across the yard at 8 a.m.

The name is misleading. Bone does not hurt while it lengthens, and the pain clusters in two age bands, roughly 3 to 5 and 8 to 12, which do not match the fastest growth. The likeliest explanation is ordinary muscle fatigue in active children. Nothing is being damaged.

Rubbing helps, and that is a clue. Massage, a heating pad, or gentle stretching usually settles growing pains in 10 to 30 minutes. An inflamed or infected joint does the opposite: touch and movement make it worse. A child who guards the leg and pushes your hand away has a different problem.

Clues That Point Away From Growing Pains

Any one of these makes growing pains unlikely. Two or more need an exam.

• Same leg, same spot, every time. Growing pains wander between both legs. Pain that returns to one fixed point, especially a spot on the bone that hurts under a fingertip press, is naming the structure involved.
• The pain is in a joint, not the muscle. Ask your child to point with one finger. If it lands on a knee, ankle, or hip rather than the meat of the thigh or calf, see Causes of Joint Pain.
• It hurts in the morning. Growing pains are over when the child wakes. Pain on waking, or stiffness that takes half an hour of moving to loosen, is the signature of joint inflammation.
• There is a limp. A limp is never growing pains, and neither is a child who will not put weight on a leg or asks to be carried.
• You can see or feel something. Swelling, warmth, redness, a firm lump, or bruises nobody can explain.
• Your child is unwell in other ways, or getting worse. Fever, weight loss, night sweats, unusual paleness, pinpoint red dots on the skin, new fatigue, or pain more intense and more frequent than it was three weeks ago.

Leg Pain That Is a True Emergency

Infection in a joint or bone. Bacteria can reach a joint space (septic arthritis) or settle in the growing end of a long bone (osteomyelitis). Inside an infected joint, pus raises the pressure and enzymes start dissolving cartilage within a day or two, so a hip or knee can be permanently damaged over one weekend. The child usually has a fever, refuses to bear weight, and holds the leg rigid and slightly turned out, screaming if you move it. That combination goes to the emergency room tonight. If fever is the loudest symptom, see our guide to fever in children.

Bloodstream infection and sepsis. Severe leg or muscle pain is one of the earliest signs of meningococcal disease and other bloodstream infections in children, often hours before the rash everyone watches for. Fever and leg pain plus cold hands and feet, blotchy or gray skin, or a spreading rash of purple or red spots that do not fade under a pressed clear glass is a 911 call.

Compartment syndrome after injury or inside a cast. The calf muscles sit in a tight sleeve of tissue. Swelling from a fracture, a hard blow, or a snug cast can raise pressure inside that sleeve until it cuts off the muscle's own blood supply. Watch for pain that keeps climbing and seems out of proportion, numbness or tingling in the toes, a calf that feels tight and shiny, and sharp pain when you gently pull the toes upward. Muscle and nerve die within hours.

Fracture and blocked blood flow. A leg that looks bent, twisted, or shortened after a fall, bone visible through the skin, or a foot that turns cold, pale, or numb below the injury needs emergency care now. Do not try to straighten the limb.

Other Causes of Leg Pain, Sorted by Age

Toddler through early school age. A limp with hip, thigh, or knee pain in the week or two after a cold is often transient synovitis, a short-lived irritation of the hip lining that clears in days. It resembles a joint infection closely enough that a doctor has to decide which it is. Between ages 4 and 8, a painless limp or nagging knee pain can be Legg-Calve-Perthes disease, a temporary failure of blood supply to the ball of the hip.

The active 8 to 14 year old. Heel pain that flares after soccer or gymnastics is usually Sever disease, the Achilles tugging on the soft growth plate of the heel. A tender bump below the kneecap in a jumping athlete is Osgood-Schlatter, the same mechanism at the shin. Both hurt with activity and quiet with rest, the reverse of growing pains.

Adolescents. Hip, groin, or knee pain in a heavier teenager who walks with the foot turned outward can be a slipped capital femoral epiphysis, where the ball of the hip slides off its growth plate like a scoop of ice cream off a cone. Knee pain in a teenager earns a hip exam for that reason. Deep bone pain near the knee or upper arm that wakes them and worsens over weeks, especially with a firm swelling, is how osteosarcoma and Ewing sarcoma start. One calf that is swollen, warm, and tender by itself, in a teenager on combined birth control pills or recently in a cast, can be a deep vein clot; chest pain or sudden breathlessness can mean the clot has reached the lungs and requires urgent medical evaluation.

Any age. Juvenile idiopathic arthritis causes joint swelling with stiffness worst on waking that eases after about 30 minutes of moving. Low iron can produce restless legs, an urge to move relieved by walking rather than rubbing. Raised purple spots over the buttocks and lower legs with joint and belly pain suggest IgA vasculitis. Bone pain that carries into the daytime with paleness, bruising, swollen glands, or returning fevers can be a first sign of leukemia, which is why a blood count belongs in the workup.

What Helps at Night, and What to Bring to the Visit

Growing pains are a diagnosis of exclusion. Your pediatrician confirms them by finding a normal exam and no red flags, not by running a test. Keep a two-week note of which leg hurt, exactly where, what time, how long it lasted, and whether your child walked normally next morning.

What settles most nights: a few minutes of firm massage on the calf or thigh, a warm heating pad or bath, and calf and hamstring stretches done during the day rather than only mid-attack. Regular daytime stretching often reduces how often the bad nights happen.

About pain medicine. Acetaminophen (Tylenol) or ibuprofen (Motrin, Advil) can help on a rough night. Follow the product label for your child's age and weight, and ask your pediatrician or pharmacist if you are unsure. Never give aspirin to a child or teenager, because of the risk of Reye syndrome. Needing medicine most nights is itself a reason to be seen. The same red flag thinking applies to head pain, covered in When Is a Headache in a Child a Red Flag?

When to Seek Medical Care