Achilles Tendon: Causes, Injuries, and What You Need to Know

When you walk, run, or push off the ground, your Achilles tendon, the strongest tendon in the human body that connects the calf muscles to the heel bone. Also known as the calcaneal tendon, it handles forces up to 10 times your body weight during activity. It’s built for power, but that also makes it vulnerable. If you’re active—whether you’re a weekend runner, a parent chasing kids, or someone who stands all day—you’ve probably felt that tightness or sharp pain behind the ankle. That’s your Achilles tendon sending a signal.

Most problems start with overuse. Achilles tendinitis, inflammation from repetitive stress without enough recovery is common in people who suddenly increase their activity. But it’s not always inflammation. Often, it’s tendinosis, a degenerative breakdown of the tendon tissue from chronic strain, which doesn’t respond to anti-inflammatories the way people expect. Then there’s the scary one: tendon rupture, a full tear that feels like a kick or snap in the back of the leg. You won’t be able to push off your foot or stand on your toes. It’s an emergency, not a nuisance.

What makes the Achilles tendon tricky is how slow it heals. Unlike muscle, tendon tissue has poor blood flow, so recovery takes weeks to months—not days. Rest alone won’t fix it. You need targeted rehab: eccentric heel drops, controlled loading, and avoiding the "wait and see" approach. Skipping physical therapy or returning too soon often leads to repeat injuries. And don’t assume it’s just an athlete’s problem. Sedentary people who suddenly start walking or climbing stairs can trigger it too, especially if they wear worn-out shoes or have tight calves.

Medications like NSAIDs might ease pain, but they don’t heal the tendon. Injections? Cortisone can weaken it further. Surgery? Only for complete tears or cases that don’t improve after 6+ months of rehab. The real fix is movement—smart, gradual, consistent movement. Strengthening the calf, improving ankle mobility, and correcting foot mechanics matter more than any pill or brace.

Below, you’ll find real-world advice on how to recognize early warning signs, what treatments actually work, and how to avoid the mistakes that turn a minor ache into a long-term problem. Whether you’re dealing with morning stiffness, post-run pain, or a sudden pop behind the heel, there’s something here that can help you move better—and stay moving.