For the past three months I have had a constant burning sensation in both thighs, like sunburn, and strong enough to interfere with my sleep.

I cycle hard. I am male, 71-years old and have cycled most of my life. Any ideas as to what is causing this problem?

Tom Murray, email

There are a number of possible causes of the burning sensation in your thighs. This may be due to degenerative changes within the lumbar spine, such as spinal stenosis, secondary to degeneration of the intervertebral discs and facet joints, reducing the size of the spinal canal. Bending forward usually relieves this pain.

The pain may be referred from your sacro-iliac, hip or knee joints. The fact that you appear to experience this pain at night makes the likeliness of a blood supply problem to the leg (external iliac artery fibrosis) low.

Various nerve entrapments may be responsible for your symptoms. A condition called Meralgia Paraesthetica is caused by compression of the lateral cutaneous nerve of the thigh in the groin area.

This normally results in altered sensation, with a burning pain over the front of the thigh, is often caused by tight clothing and may be eased by wearing looser-fitting shorts or weight loss. Pain at the back of the thigh conversely may be caused by entrapment of the posterior cutaneous nerve of the thigh or the sciatic nerve.

I would recommend that you visit a doctor for a thorough examination in order to make an accurate diagnosis and organise treatment.

Andrew Meilak

Sports doctor. First-category road racer and physio at Westcombe Park rugby club