Plantar fasciitis

Plantar fasciitis is a common cause of pain under the heel. The plantar fascia is a thick band of tissue that runs along the sole of the foot, from the heel bone to the toes, and supports the arch. When it is overstretched or overused it can become swollen and sore.

It is not dangerous. Most people recover with simple treatment, although it can take months.

The main symptom is pain and stiffness under the heel, which may be dull or sharp. It often follows this pattern:

• Worst with the first steps after sleeping or sitting for a long time
• Easier once you are moving, but back after long standing, walking or running
• Sore when you climb stairs or raise your toes, which stretches the sole
• Coming on gradually, or sometimes suddenly after strenuous activity

See a doctor if the pain is severe or stops normal activities, keeps coming back or is getting worse, or has not improved after two weeks of self-care. Also see a doctor for sudden severe heel pain, a red or swollen heel, or tingling or loss of feeling in the foot. Anyone with diabetes who has foot pain should have it checked, because foot problems can be more serious.

The plantar fascia is put under more strain than it can take, so it becomes irritated and swollen. It can follow a sudden increase in standing, walking or running, starting exercise on hard surfaces, or exercising with a tight calf muscle or heel.

• Being aged 40 to 60
• Flat feet or high arches
• A tight Achilles tendon or calf muscles
• Long-distance running, or running on hard or uneven ground
• Long hours standing or walking, or a sudden rise in activity
• Shoes with poor arch support or thin, soft soles
• Being overweight, or putting on weight quickly

Serious complications are uncommon. The pain can:

• Last for many months, and sometimes up to two years
• Come back after it has settled
• Make standing, walking and exercise painful
• Need a steroid injection or, rarely, surgery when simple treatment does not work

• Wear supportive, cushioned shoes, and avoid high heels, flip-flops and walking barefoot on hard floors
• Keep the calf muscles, Achilles tendon and sole flexible with regular stretching, including before getting out of bed
• Build up walking, running and other activity gradually
• Avoid long periods standing on hard surfaces
• Keep to a healthy weight

A doctor usually diagnoses plantar fasciitis from your story and an examination of the foot, which may show tenderness along the sole, flat feet or high arches, and tight calf muscles. An X-ray is not always needed, but may be done to rule out other causes of heel pain, such as a broken heel bone.

Most people improve with self-care. Rest the foot and stop activities that bring on the pain, and choose low-impact exercise such as swimming. Ice wrapped in a cloth can ease pain. Regular gentle stretches of the sole and calf, cushioned shoes, and insoles or heel pads help. Paracetamol or ibuprofen can ease the pain, but ibuprofen does not suit everyone, so check with a doctor or pharmacist.

A physiotherapist can teach stretching exercises, and a foot specialist can advise on insoles, footwear or a night splint, which holds the foot gently stretched during sleep.

If these do not help, a doctor may suggest a walking boot for a few weeks, custom shoe inserts, a steroid injection into the heel, or shock-wave therapy, which uses sound waves. Surgery is rarely needed.