What Is an Achilles Tendon Injury?

Medically Reviewed by Jabeen Begum, MD on December 15, 2023
10 min read

An Achilles tendon injury can happen to anyone, whether you're an athlete or just going about your daily life.

The Achilles tendon is the largest tendon in your body. It stretches from the bones of your heel to your calf muscles. You can feel it: a springy band of tissue at the back of your ankle and above your heel. It lets you point your toes toward the floor and raise up on your tiptoes. Thanks to its dense fibers, your Achilles tendon is also quite strong, able to withstand the force of up to 1,100 pounds.

But because this part of your leg doesn't have great blood flow, it's easy to injure your Achilles tendon. Your doctor might call this tendinitis or tendonitis. It can feel like a burning or stiffness in the lower part of your leg. If the pain is severe, your Achilles tendon may be partly or completely torn.

Some common signs that you've hurt your Achilles tendon include:

  • Tight Achilles tendon in the morning
  • Stiffness or pain along your Achilles tendon
  • Pain that gets worse with activity
  • Heel pain when you wear shoes
  • Severe pain the day after physical activity
  • Thickening
  • Bone spurs (bony growths)
  • Swelling that doesn't go away, or gets better then returns

Achilles tendon pain

The most obvious sign of an Achilles tendon injury is pain above your heel, especially when you stretch your ankle or stand on your toes. It may be mild and get better or worse over time. If your Achilles tendon tears, or ruptures, the pain will start all of a sudden and can be severe. It's best to see a doctor right away if this happens.

Achilles tendon lump

It's common to get a lump on your Achilles tendon after you hurt it. Sometimes this is due to swelling, and can be a sign of moderate Achilles tendinitis. If it's been there for a while, it could also mean that the area is trying to heal.

There are two main types of tendinitis that affect different parts of your tendon:

  • Noninsertional Achilles tendinitis. In this type of injury, fibers in the middle of your tendon break down, swell, and get thick. It's more common in very active people, especially runners.
  • Insertional Achilles tendinitis. This affects the lower part of your heel, where your tendon inserts, or goes into, your heel bone. It's more likely to cause bone spurs. Although insertional Achilles tendinitis is also common in runners, it can happen to anyone, even if you're not very active. It's often due to tight calf muscles, which put more stress on your Achilles tendon.

You can have one of these types of tendinitis, or both at the same time. 

Other Achilles tendon injuries include:

Achilles bursitis

At the back of your heel is a fluid-filled sac called a bursa. It cushions your Achilles tendon when it slides over your heel bone. If you overuse your ankle or foot, this bursa can become irritated and inflamed. It could also happen because of a health issue like arthritis or gout, or if you wear shoes that are too tight and rub against your heel. Another name for Achilles bursitis is retrocalcaneal bursitis.

Achilles tendon rupture

If your Achilles tendon tears in half or comes off your heel bone, you may hear a snapping or popping noise when it happens. This is an Achilles rupture and is different than tendinitis. The pain is often instant and severe. You could have bruising and swelling. You may also have trouble pointing your toes and pushing off your toes when you take a step.

Achilles tendinitis vs. tendinosis

These conditions sound similar,  but they're not the same. 

Achilles tendonitis or tendinitis means that your tendons are inflamed. It's a short-term condition. 

Achilles tendinosis means that you have ongoing, or long-term, tendinitis. The cells in your tendons have started to break down, which can alter how well your Achilles tendon functions.

Achilles tendon injuries are common if you do activities where you quickly speed up, slow down, or pivot, such as:

  • Running
  • Gymnastics
  • Dance
  • Football
  • Soccer
  • Baseball
  • Softball
  • Basketball
  • Tennis
  • Volleyball

These injuries tend to happen when you start moving suddenly as you push off and lift your foot rather than when you land. For instance, a sprinter might get hurt at the start of a race as they surge off the starting block. The abrupt action can be too much for your tendon to handle. 

You can also injure your Achilles tendon if you stress it over and over again with high-impact activities. These are known as repetitive stress injuries.

But you don't have to be an athlete to get this kind of injury. If you step into a hole or fall from a high place, you could rupture your Achilles.


Many factors make you more likely to get an Achilles tendon injury:

  • You wear high heels, which can stress the tendon.
  • You have "flat feet," also called fallen arches. This means that when you take a step, the impact causes the arch of your foot to collapse, stretching the muscles and tendons.
  • Your leg muscles or tendons are very tight.
  • You have bone spurs.
  • You add time to your exercise routine or do more intense activity.
  • You start a new type of exercise.
  • You wear shoes that don't fit well or aren't right for the kind of physical activity you do.
  • You work out on uneven surfaces.
  • You take medicines called glucocorticoids or antibiotics called fluoroquinolones.
  • You have a chronic condition that can weaken your Achilles, like rheumatoid arthritis, lupus, gout, or diabetes.

Your risk of a ruptured Achilles tendon is higher if you are:

  • Assigned male at birth
  • Between 30 and 40 years old 
  • Doing a sport that involves a lot of running and jumping
  • Getting steroid shots in your ankle (it may weaken the nearby Achilles tendon)
  • Carrying extra weight 

Doctors sometimes mistake an Achilles tendon injury for a sprained ankle. To make the right diagnosis, your doctor will start with a physical exam. They may want to see you walk or run so they can look for an issue that might have led to your injury.

They also might do something called the calf squeeze test. You'll kneel on a chair or bench or lie on your stomach on the exam table. Your doctor will gently squeeze the calf muscle on your healthy leg. This will pull on the tendon and make your foot move. Next, they'll do the same thing on your other leg. If your Achilles tendon is torn, your foot won't move because your calf muscle won't be connected to your foot.

Your doctor may test your range of motion to see if you can move your ankle the way you should. They may also do imaging tests, such as an X-ray or MRI. These tests can show what kind of tendon damage you have and help them decide on the best treatment for you.

Minor to moderate Achilles tendon injuries usually heal on their own. To speed the process, you can:

Rest your leg. Avoid putting weight on it as best you can. You may need crutches.
Ice it. Ice your injury for up to 20 minutes at a time as needed.
Compress your leg. Use an elastic bandage around the lower leg and ankle to keep down swelling.
Raise (elevate) your leg. Prop it on a pillow when you're sitting or lying down.
Take anti-inflammatory painkillers. Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and naproxen can help with pain and swelling. Follow the instructions on the label to help prevent side effects, such as bleeding and ulcers. Take them with food. Check with your doctor first if you have any allergies, have an ongoing medical condition, or take any other medication or supplements. If you feel like you need NSAIDs for longer than 7 to 10 days, let your doctor know.
Use a heel lift. Your doctor may recommend that you wear an insert in your shoe while you recover. It can help protect your Achilles tendon from further strain. Ask your doctor which heel lift is best for you.
Practice stretching and strengthening exercises. Your doctor or physical therapist can recommend ones for you to try. 
Take part in low-impact activities. When your doctor says it's OK, activities like swimming can help promote healing. 

Achilles tendinitis brace

If your sprain is mild, your doctor may show you how to tape your Achilles tendon. A special flexible bandage called kinesiology tape (KT tape) can take pressure off your Achilles tendon when you're being active. If your injury is severe, your doctor may want you to keep your ankle from moving at all at first. They could fit you for a walking boot, splint, or a cast that keeps your foot flexed down. Or they could suggest a night splint. You'll put it on at bedtime to keep your Achilles tendon stretched while you sleep.

Signs to seek care right away

An Achilles tendon injury isn't an emergency, but if you have any of the following symptoms, call your doctor for advice or go to an urgent care clinic:

  • You heard a "pop" or "snap" at the time of the injury.
  • You can't bear weight on your foot or ankle.
  • The pain keeps you up at night.
  • Your leg is swelling.
  • Your foot or ankle turns a different color.
  • Your foot or ankle feels hotter or colder than the rest of your leg.
  • You have signs of an infection (like a high fever or feeling run down).

If your Achilles is torn, your doctor may recommend surgery. The younger and more active you are, the more likely that surgery will be the best option.

You should have the surgery within 4 weeks of the injury. Your surgeon will make a small incision in the back of your ankle and sew the Achilles back together. Sometimes they'll need to sew other tendons in to make it even stronger. Between 80% and 90% of these operations are successful.

Your doctor could decide not to do surgery if you're older and less active, or if you have only a partial tear.

The nonsurgical route will involve lots of physical therapy and doing stretches and exercises on your own. You might also have ultrasound or shockwave therapy. You may have to wear a cast, a walking boot, or heel cups to take pressure off the tendon and keep it from moving.

You'll have a longer road to full recovery, and you'll run a bigger risk of reinjuring the tendon.

Recovery may take months, but it depends on how serious your injury is. Different conditions heal at different speeds.

You can still be active while your injury heals. Ask your doctor what's OK to do. But don't rush things. Wait to return to your old level of physical activity until:

  • You can move your leg as easily and freely as your uninjured leg.
  • Your leg feels as strong as your uninjured leg.
  • You don't have any pain in your leg when you walk, jog, sprint, or jump.

If you push yourself too much before your Achilles tendon injury fully heals, you could get injured again, and the pain could become a long-lasting problem. You may be able to avoid some of these issues if you replace high-impact sports like running with low-impact workouts. Activities like swimming and cycling put less stress on your tendon.

To protect your Achilles tendons, try to:

  • Stretch and strengthen your calves.
  • Take time to warm up and cool down after a workout.
  • Avoid running or doing other types of exercise on uneven surfaces.
  • Increase the length or intensity of your workouts little by little.
  • Wear shoes with good support that fit well.
  • Stop exercising if you feel pain or tightness in the back of your calf or heel.

Strengthening your calf muscle takes stress off your Achilles tendon. Stretches like these are easy to do at home, but your doctor can confirm if they're right for you.

Calf stretch: Lean into a wall from about an arm's length distance away. Keep one leg straight and your heel on the ground. Place your other leg closer to the wall, bend your knee, and press your hips slightly toward the wall. You should feel a stretch in the back of your straightened leg. Hold for 10 seconds, then switch. Repeat up to 20 times per side.

Calf raise: Sit in a chair with your feet flat on the ground. Attempt to lift your heels while keeping the balls of your feet on the floor. Hold for 30 seconds and repeat 5 times.

Lower calf strengthener: Stand in front of a counter, your knees slightly bent. Holding onto the counter, slowly rise onto your toes, then lower back down. Aim for 30 reps.

It's surprisingly easy to injure your Achilles tendon, the large, cord-like tendon that stretches from your heel to your calf muscle--especially if you run. Many strains heal with home care, while more severe injuries may need physical therapy or surgery. Stretching your lower leg and strengthening your calf muscle is the best way to protect your Achilles tendon.   

How long does it take a strained Achilles tendon to heal?

The most common place to injure your Achilles tendon is where it joins your calf muscle. Because this area gets less blood flow than the more muscular part of your leg, it can be slow to heal. You may have symptoms for a few months.

If you have an Achilles tendon tear or rupture and need surgery, it could be a year before you're as active as you were before. Following your doctor's advice and working with a physical therapist will be important for your recovery.