Achilles Tendinitis: Why It Won't Heal and What Actually Works

It starts as stiffness in the back of your heel or lower calf when you first get up in the morning. You walk it off and forget about it. Then it starts showing up at the beginning of a run, during a long day on your feet, or while climbing stairs. Eventually it's there most of the time, and rest doesn't seem to make it go away anymore.

Achilles tendinitis — inflammation of the large tendon that connects the calf muscles to the heel bone — is one of the most frustrating foot and ankle conditions to deal with. It's common, it's stubborn, and it has a bad habit of lingering for months when it's not managed properly.

Why the Achilles Is Vulnerable

The Achilles tendon is the thickest and strongest tendon in the body, handling forces of up to 12 times your body weight during running. But it has one critical weakness: poor blood supply. The mid-portion of the tendon — about 2 to 6 centimeters above where it attaches to the heel — receives the least blood flow of any section. This is exactly where most Achilles problems develop, and it's why healing is slow.

Tendon healing requires blood to deliver oxygen, nutrients, and repair cells. A structure with limited blood supply heals at a fraction of the speed of well-vascularized tissue like muscle. This is the fundamental reason Achilles tendinitis is so persistent.

Tendinitis vs. Tendinopathy

An important distinction: early-stage Achilles problems involve actual inflammation (tendinitis). But if the condition has been present for more than a few weeks, the tendon tissue typically transitions from inflamed to degenerative — a condition more accurately called tendinopathy. The difference matters because anti-inflammatory treatments (ice, NSAIDs, cortisone) work well for acute tendinitis but are less effective for chronic tendinopathy, where the issue is tissue degeneration rather than active inflammation.

This is why many patients find that ibuprofen and ice help initially but stop working over time — the nature of the problem has changed.

Common Causes

Achilles tendinitis typically develops from a combination of factors. Sudden increases in activity (ramping up running mileage, starting a new sport, or transitioning to minimalist shoes too quickly) are a classic trigger. Tight calf muscles place chronic tension on the tendon. Flat feet or overpronation alter the angle of pull on the Achilles, creating uneven stress. Age-related changes reduce the tendon's elasticity and blood supply. And footwear that doesn't provide adequate heel support allows excessive tendon strain.

Why Rest Alone Isn't Enough

The most common advice for Achilles tendinitis — "just rest it" — is incomplete. Complete rest reduces pain because you're removing the load, but it doesn't stimulate the tendon to heal and strengthen. When you resume activity, the undertreated tendon quickly becomes symptomatic again because nothing has actually changed in the tissue.

Research consistently shows that controlled, progressive loading is the most effective approach for Achilles tendinopathy. The gold standard is eccentric exercise — specifically, slow heel drops off a step — which lengthens the tendon under load, stimulating remodeling and strengthening of the degenerative tissue.

What Actually Works

Effective Achilles treatment is multi-pronged:

• Eccentric loading exercises: The cornerstone of recovery. Done correctly and consistently, these produce measurable improvement in 6–12 weeks for most patients.
• Heel lifts and orthotics: A temporary heel lift reduces the strain on the Achilles, while custom orthotics correct biomechanical issues like overpronation that contributed to the problem.
• Shockwave therapy: Focused shockwave therapy (ESWT) is one of the most effective treatments for chronic Achilles tendinopathy. The acoustic waves stimulate blood flow and cellular repair in tissue that otherwise heals poorly. It's particularly valuable for cases that haven't responded to exercises alone.
• Laser therapy: Laser and H-Wave therapy can reduce pain and accelerate healing at the cellular level.
• Activity modification: Not complete rest, but smart modification — reducing high-impact activities while maintaining controlled loading through the exercise program.

What to Avoid

Cortisone injections into or near the Achilles tendon are generally avoided. Unlike other areas of the foot, cortisone in the Achilles region carries a real risk of tendon rupture — weakening an already compromised tendon. Stretching into pain is also counterproductive — gentle stretching below the pain threshold is fine, but aggressive stretching of an inflamed or degenerated tendon makes things worse.

The Bottom Line

If your Achilles has been hurting for more than two weeks, or if it improved with rest but came back when you resumed activity, the tissue needs more than time — it needs targeted treatment. The sooner you start the right approach, the shorter the recovery. Call (760) 728-4800 to get evaluated.