Pain in the back of your heel or ankle can make every step feel uncertain. The Achilles tendon plays a key role in walking, running, jumping, and pushing off the ground, so even mild discomfort can interfere with daily movement and athletic performance.

Two of the most common causes of Achilles pain are tendinitis, also called tendinopathy, and an Achilles tear. While both involve the same tendon, they are very different injuries and require different approaches to treatment. Understanding the signs can help you know when it may be time to seek care.

Read on as Orlin & Cohen’s Jared Kipnis, DPT, explains how to tell the difference and why an accurate diagnosis matters.

Two Injuries, One Sore Heel

The Achilles tendon is the thick band of tissue that connects the calf muscles to the heel bone. It is one of the strongest tendons in the body, but it is also placed under significant stress during activity. Every time you walk, climb stairs, run, jump, or rise onto your toes, the Achilles tendon helps generate power and control.

Due to the load this tendon handles daily, pain can develop gradually from overuse or suddenly from a traumatic or sports-related injury. The key is determining whether the tendon is irritated and overloaded or whether the fibers have partially or completely torn.

What Achilles Tendinitis Feels Like

Achilles tendinitis, or tendinopathy, typically develops over time. It often affects runners, athletes, and active individuals, but it can also occur in people who suddenly increase their activity level or spend long periods on their feet.

The pain usually starts as stiffness or soreness at the back of the ankle, often a few centimeters above where the tendon attaches to the heel. Many people notice stiffness in the morning that improves once they begin moving. Pain may also feel better after warming up, but return during or after activity.

Tenderness, swelling, or thickening along the tendon may also occur. The important distinction is that with tendinopathy, the tendon is irritated and overloaded but not fully torn.

What an Achilles Tear Feels Like

An Achilles tear is a more serious injury. A complete tear, or rupture, often happens suddenly during a forceful movement such as sprinting, jumping, pushing off, or changing direction quickly. Many people describe hearing or feeling a pop, followed by immediate sharp pain in the back of the ankle or calf.

Walking becomes difficult, and pushing up onto the toes may be impossible. Some patients feel as though they were kicked in the back of the leg, even though no contact occurred.

Partial tears can be harder to recognize because they may feel like tendinitis. Pain may be more localized or persistent, and symptoms may not always be as dramatic as a full rupture. That is why a professional evaluation is important when Achilles pain does not improve or follows a sudden injury.

How to Tell Them Apart

The start of the pain

One of the biggest clues is how the pain began. Achilles tendinitis usually comes on gradually over days, weeks, or months. It may begin as mild soreness and slowly become more noticeable with activity.

An Achilles tear usually has a more sudden onset. It often occurs during a specific movement and is immediately painful. If you remember the exact moment something happened, especially with a pop or sudden loss of strength, a tear may be more likely.

How the pain behaves

Tendinitis pain often changes with activity. It may feel stiff at first, loosen up with movement, and then worsen later in the day or after exercise. Rest may reduce symptoms temporarily, but the pain often returns when the tendon is loaded again.

With a tear, the pain is typically sharper and more immediate. Movement does not usually make it feel better, and weakness is more prominent. Difficulty walking, pushing off, or rising onto the toes should be taken seriously.

What an exam and imaging reveal

An orthopedic specialist or physical therapist can evaluate the tendon by checking tenderness, strength, range of motion, and overall function. In cases of a tear, there may be a gap in the tendon that can be felt during examination. A Thompson test, where the calf is gently squeezed to see whether the foot moves, may help identify a rupture.

If the diagnosis is unclear, diagnostic imaging may be recommended. Ultrasound is often used because it can show the tendon in real time. MRI may be helpful in more complex cases or when surgery is being considered.

Why the Right Diagnosis Changes Everything

Treating Achilles tendinitis

For Achilles tendinitis, complete rest is usually not the answer. Treatment often focuses on guided tendon-loading exercises, activity modification, strengthening, and improving flexibility and mechanics. Physical therapy can help patients gradually rebuild the tendon’s tolerance to load while staying active within a safe range.

Treating an Achilles tear

A complete Achilles tear may require immobilization, bracing, or surgery, depending on the severity of the injury and the patient’s goals. Recovery is typically longer and requires a structured rehabilitation plan to restore strength, mobility, and function.

When to See a Doctor

You should seek medical evaluation if Achilles pain does not improve, worsens with activity, or follows a sudden pop or sharp pain. Difficulty walking, inability to push off, swelling, bruising, or weakness when rising onto your toes may signal a more serious injury.

Get an Accurate Diagnosis at Orlin & Cohen

Achilles pain can be frustrating, but guessing at the cause can delay recovery. At Orlin & Cohen, our fellowship-trained foot and ankle specialists can evaluate your symptoms, determine whether you are dealing with tendinitis, a partial tear, or a more serious rupture, and recommend the right treatment plan.

If pain in the back of your ankle is keeping you from moving comfortably, schedule an appointment today and get back to the activities you love.