Achilles tendinitis is an overuse injury of the Achilles (uh-KILL-eez) tendon, the band of tissue that connects calf muscles at the back of the lower leg to your heel bone.
Achilles tendinitis most commonly occurs in runners who have suddenly increased the intensity or duration of their runs. It's also common in middle-aged people who play sports, such as tennis or basketball, only on the weekends.
Most cases of Achilles tendinitis can be treated with relatively simple, at-home care under your doctor's supervision. Self-care strategies are usually necessary to prevent recurring episodes. More-serious cases of Achilles tendinitis can lead to tendon tears (ruptures) that may require surgical repair.
The pain associated with Achilles tendinitis typically begins as a mild ache in the back of the leg or above the heel after running or other sports activity. Episodes of more-severe pain may occur after prolonged running, stair climbing or sprinting.
You might also experience tenderness or stiffness, especially in the morning, which usually improves with mild activity.
When to see a doctor
If you experience persistent pain around the Achilles tendon, call your doctor. Seek immediate medical attention if the pain or disability is severe. You may have a torn (ruptured) Achilles tendon.
Achilles tendinitis is caused by repetitive or intense strain on the Achilles tendon, the band of tissue that connects your calf muscles to your heel bone. This tendon is used when you walk, run, jump or push up on your toes.
The structure of the Achilles tendon weakens with age, which can make it more susceptible to injury — particularly in people who may participate in sports only on the weekends or who have suddenly increased the intensity of their running programs.
A number of factors may increase your risk of Achilles tendinitis, including:
- Your sex. Achilles tendinitis occurs most commonly in men.
- Age. Achilles tendinitis is more common as you age.
- Physical problems. A naturally flat arch in your foot can put more strain on the Achilles tendon. Obesity and tight calf muscles also can increase tendon strain.
- Training choices. Running in worn-out shoes can increase your risk of Achilles tendinitis. Tendon pain occurs more frequently in cold weather than in warm weather, and running on hilly terrain also can predispose you to Achilles injury.
- Medical conditions. People who have psoriasis or high blood pressure are at higher risk of developing Achilles tendinitis.
- Medications. Certain types of antibiotics, called fluoroquinolones, have been associated with higher rates of Achilles tendinitis.
Achilles tendinitis can weaken the tendon, making it more vulnerable to a tear (rupture) — a painful injury that usually requires surgical repair.
While it may not be possible to prevent Achilles tendinitis, you can take measures to reduce your risk:
- Increase your activity level gradually. If you're just beginning an exercise regimen, start slowly and gradually increase the duration and intensity of the training.
- Take it easy. Avoid activities that place excessive stress on your tendons, such as hill running. If you participate in a strenuous activity, warm up first by exercising at a slower pace. If you notice pain during a particular exercise, stop and rest.
- Choose your shoes carefully. The shoes you wear while exercising should provide adequate cushioning for your heel and should have a firm arch support to help reduce the tension in the Achilles tendon. Replace your worn-out shoes. If your shoes are in good condition but don't support your feet, try arch supports in both shoes.
- Stretch daily. Take the time to stretch your calf muscles and Achilles tendon in the morning, before exercise and after exercise to maintain flexibility. This is especially important to avoid a recurrence of Achilles tendinitis.
- Strengthen your calf muscles. Strong calf muscles enable the calf and Achilles tendon to better handle the stresses they encounter with activity and exercise.
- Cross-train. Alternate high-impact activities, such as running and jumping, with low-impact activities, such as cycling and swimming.