Usually caused by continuous and repetitive stress on the affected area, it can also occur due to sudden injury, poor stretching or conditioning before exercise or playing high risk sports.

Achilles Tendonitis is also more likely to occur when:

- You do not have shoes with good support

- You jump a lot (such as when playing basketball)

- You run on hard surfaces such as concrete or you run too often

- You suddenly increase the amount or intensity of an activity

- Your calf muscles are very tight (not stretched out)

- Your foot suddenly turns in or out

Tendonitis can also occur when a bone spur forms at the back of the heel. This can irritate the Achilles Tendon, causing pain and swelling, and is more common among older people.

Achilles Tendonitis tends to exhibit various painful and swollen symptoms at the back of the heel. You should consult your doctor if you:

- Are unable to bend the ankle

- Are unable to walk comfortably on the affected side

- Experience swelling of the calf

- Have an injury that causes deformity around the joint

- Have ankle pain at night or while you are resting

- Have ankle pain for longer than a few days

- Experience signs of infection, including fever, redness or warmth

Depending on the cause of the problem, treatment may include:

- Heat pads to relax muscles and stimulate blood flow

- Ice packs to minimise swelling

- Non-steroidal anti-inflammatory drugs to treat pain

- Physiotherapy to increase strength and regain mobility

- Rest to treat inflammation

- Steroid injections to treat inflammation

- Stretching to loosen the calf muscle

Surgery is usually only offered for recurrent injuries and persistent pain, but may be needed if the tendon tears or there are loose ligaments.

If left untreated, this may lead to a rupture of the Achilles tendon, causing severe sharp pain. Surgical repair is almost always necessary at this point.