Inflammation of the Achilles tendon is common among sportspeople, whether amateur or professional.

The Achilles tendon is a large, thick tendon that connects the calf muscles to the heel bone (it's named after the Greek god Achilles who, according to mythology, was vulnerable only at his heel). You can feel your Achilles tendon at the back of your ankle - it's the thick, springy tissue just above the heel.

Although it's the largest tendon in the body and can withstand immense force, the Achilles is surprisingly vulnerable. It's the most frequently ruptured tendon in the body - runners and jumpers particularly fear a ruptured Achilles tendon, which feels like a very painful sudden kick in the back of the ankle and needs urgent repair. Inflammation of the tendon, or Achilles tendonitis, is more common.

The symptoms

There are several conditions that can cause similar symptoms, such as inflammation of a heel bursa (or fluid sac) or a partial tear of the tendon. You should see your doctor to confirm what's causing your symptoms.

The symptoms of Achilles tendonitis include:

• Mild pain after exercise or running that gradually gets worse
• Localised pain along the tendon during or a few hours after running, which may be quite severe
• Localised tenderness of the tendon about 3cm above the point where it joins the heel bone, especially first thing in the morning
• Stiffness of the lower leg, especially first thing in the morning.
• Swelling or thickening around the tendon

How it's treated

The treatment of Achilles tendonitis depends on the severity of the injury and whether you're a professional sportsperson. Treatment includes:

• Rest, to allow the inflammation to settle. Any sport that aggravates the tendon should be stopped for at least a week, although exercise that doesn't stress the tendon, such as swimming, may be possible
• Regular pain relief with non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen
• Steroid injections
• Bandaging and orthotic devices, such as shoe inserts and heel lifts, to take the stress off the tendon
• Physiotherapy to strengthen the weak muscle group in the front of the leg and the upward foot flexors
• Surgery (rarely needed) to remove fibrous tissue and repair tears

Possible triggers

To help prevent another attack, it's important to know what triggers Achilles tendonitis in the first place.

Triggers may include:

• Overuse of the tendon - the result of a natural lack of flexibility in the calf muscles. Ask your coach about exercises specifically to improve calf muscle flexibility, and ensure your running shoes cushion the heel fully
• Starting up too quickly, especially after a long period of rest from sport - always warm up thoroughly
• Rapidly increasing running speeds or mileage - build your activity slowly, by no more than ten per cent a week.
• Adding stair climbing or hill running to a training programme too quickly
• Sudden extra exertion, such as a final sprint

This article was last medically reviewed by Dr Trisha Macnair in October 2007