Because stress fractures of the calcaneus (heel bone) and tibia and fibula (lower-leg bones) share similar symptoms, investigations and treatments, we're grouping them together here.

Symptoms
As with all stress fractures, you'll feel crescendo pain, which grows in intensity the longer and further you run, probably reaching an intolerable peak just before you stop. In the textbook case, the pain comes on sooner and more severely with each successive run.

Signs
It's important that your GP listens to your description, for there is often little to feel at the site of the fracture. A 'pinch test' can confirm a stress fracture of the calcaneus (heel bone) earlier than you'd be able to feel the swelling of healing callus in the tibia or fibula.

Medical investigations
An x-ray may not reveal the early stages of a stress fracture, so an ultrasound test or scan is a better option. This can be particularly useful for headstrong athletes who may continue to run through the pain and tenderness until the bone snaps completely.

What else could it be?
A variety of illnesses, infections or even growths can cause bone pain - various tests can confirm or eliminate the possibility of their existence.

Self-treatment
Rest! (This doesn't mean you shouldn't work out your cardiovascular system and the rest of your body with exercise that doesn't make the fracture hurt.)

Medical treatment
Despite your protests, your doctor will continue to emphasise the need to rest the fractured limb. If the fracture hasn't healed within six to eight weeks, they'll need to check that bony union is in fact occurring - if it's not, they may have to consider further measures, including surgery and bone grafting. On a positive note, a healed stress fracture is usually stronger than the original bone.

Can you run through it?
No. Any runner who attempts to run through a proven stress fracture probably needs their head examined, as the chances of worsening the injury are so high.

Recovery time
A stress fracture usually recovers in half the time that a complete break of the same bone would, ie six to eight weeks.