Pain in the back of the ankle is often described as “Achilles tendonitis,” but that term isn’t always accurate. In many cases, the problem is actually Achilles tendinosis, a similar-sounding but separate condition that requires a different treatment approach.
Understanding the difference between tendonitis and tendinosis can help you get the right care. Perhaps most important, it can help you avoid long-term tendon damage. Below, we examine the differences, available treatment options, and when to consult a specialist.
What Is the Achilles Tendon?
The Achilles tendon is the strong, fibrous band that connects your calf muscles to your heel bone. It plays a crucial role in:
- Walking
- Running
- Jumping
- Pushing off your foot
Because it handles so much stress, it’s one of the most commonly injured tendons in the body, especially in active individuals.
What Is Achilles Tendonitis?
Achilles tendonitis is an inflammatory condition. It typically develops from:
- Sudden increases in activity
- Overuse
- Poor footwear
- Tight calf muscles
- Training errors in runners or athletes
Common Symptoms of Tendonitis
- Pain that improves with rest
- Pain or stiffness along the tendon
- Tenderness when touching the area
- Mild swelling
Treatment Options for Tendonitis
Treatment focuses on reducing inflammation and allowing the tendon to heal. This may include:
- Activity modification or rest
- Ice and anti-inflammatory medications
- Supportive footwear or heel lifts
- Physical therapy
- Stretching and strengthening exercises
Most patients recover with conservative, non-surgical treatment.
What Is Achilles Tendinosis?
Achilles tendinosis is a degenerative condition, not an inflammatory one. It develops when repeated stress causes small injuries in the tendon that don’t heal properly over time.
Instead of inflammation, the tendon experiences:
- Microscopic tears
- Thickening of the tendon
- Breakdown of normal tendon fibers
This process can make the tendon weaker and more prone to rupture if left untreated.
Common Symptoms of Tendinosis
- Chronic pain or stiffness, especially in the morning
- Thickening or a noticeable lump along the tendon
- Persistent discomfort during or after activity
- Pain that does not improve with rest alone
Tendinosis typically develops over months or even years, rather than suddenly.
Key Differences Between Tendonitis and Tendinosis
Achilles Tendonitis | Achilles Tendinosis |
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Because the underlying causes are different for these conditions, the treatments differ as well.
Treatment Options for Tendinosis
Tendinosis involves degeneration rather than inflammation, so treatment focuses on stimulating tendon healing and strengthening the tissue.
Common treatment options include:
- Targeted physical therapy
- Activity modification
- Supportive footwear or orthotics
- Shockwave therapy in some cases
If conservative treatment doesn’t provide relief, advanced options such as minimally invasive procedures or surgery may be considered to remove damaged tissue and restore tendon function.
When to See a Specialist for Achilles Conditions
If you’ve had Achilles pain that:
- Lasts more than a few weeks
- Keeps coming back
- Is getting worse over time
- Limits your ability to walk, run, or exercise
… then it may be time for a professional evaluation by a foot and ankle specialist. Early treatment can help prevent more serious complications, including tendon rupture.
Get the Right Treatment Plan for Achilles Pain
Because tendonitis and tendinosis require different approaches, an accurate diagnosis is essential. A thorough evaluation can determine the exact cause of your symptoms and the most effective path to recovery.
We’re here to help! Contact Seattle foot and ankle surgeon Jonathan Hall, MD, FAAOS to discuss your Achilles pain and explore treatment options that help you return to comfortable, confident movement.