Exposure to extreme temperatures and thigh injuries may cause a burning pain in the upper thigh, according to Healthgrades. In some situations, the pain may be due to nerve problems as a result of lupus, diabetes or multiple sclerosis. Another possible cause is meralgia paresthetica, which occurs due to compression of the lateral femoral cutaneous nerve, explains Mayo Clinic.
The lateral femoral cutaneous nerve is a sensory nerve that does not affect a patient's ability to use their legs, explains Mayo Clinic. When this nerve is pinched, the patient experiences a burning sensation in their upper thigh. This often happens when the nerve is trapped due to increased pressure around the groin area.
Pregnancy, tight clothes and wearing a heavy tool belt may compress the lateral femoral cutaneous nerve and cause meralgia paresthetica, states Mayo Clinic. Other causes of pressure on this nerve are scar tissue around the inguinal ligament, pregnancy and weight gain.
Diabetes may cause nerve injury and result in pain in the upper thighs, explains Mayo Clinic. Another possible cause is a seat belt injury after a car accident. If the patient experiences other symptoms in addition to the burning sensation in the thighs, such as weakness on one side of the body or numbness, it could be a sign of a stroke, according to Healthgrades.