What It Is
Sever's disease (calcaneal apophysitis) is irritation of the growth plate at the back of the heel, where the Achilles tendon attaches. Despite the name, it's not a disease — it's a repetitive strain injury that shows up during growth spurts, most often between ages 8 and 14, and it causes no lasting damage.
What Contributes to It
Tight calf and Achilles tendon — bones can grow faster than the tendon during a growth spurt
High-impact sports on hard surfaces
Flat feet
A recent growth spurt or jump in activity level
What You'll Notice
Common signs in an active kid:
Heel pain with running, jumping, or standing
Pain that's worse after activity or first thing in the morning
Limping or walking on tiptoes
Tenderness when the sides of the heel are gently squeezed
How We Treat It
Reduce the irritating load — a temporary cutback in high-impact activity, not a full stop.
Stretch the calf and Achilles — consistent, gentle stretching eases tension on the growth plate.
Support the heel — cushioned shoes and heel cups or orthotics as needed.
Return to sport gradually — building back up as symptoms ease.
Bottom line: Most kids are back to full activity within a few weeks to months, and symptoms resolve completely once the growth plate finishes closing, usually around age 15. This is a normal part of growing, not a lasting problem.