Pain and numbness on either the left or right thigh can be caused by meralgia paresthetica, peripheral neuropathy, multiple sclerosis and lupus, explains Healthgrades. Some other causes include injury, obesity, trauma and tight clothing, notes the American Academy of Orthopaedic Surgeons.
There are several possible causes for thigh pain and numbness, among which is sciatica, according to Healthgrades. When the sciatic nerve that runs down the leg becomes pinched or pressured in the back, it causes numbness and pain. Another possible cause is peripheral neuropathy when the nerves start to malfunction or become diseased. This is often a result of diabetes or alcoholism. If this issue goes untreated, more serious complications can occur such as permanent nerve damage, disability and paralysis. Brain damage is another possibility if the cause of pain is due to a stroke.
Meralgia paresthetica is a condition in which the nerves in thighs become compressed, causing burning pain and numbness, states the American Academy of Orthopaedic Surgeons. These nerves become compressed due to several reasons such as trauma to the leg that causes the tissue to swell or tight clothing that puts pressure on the nerves. Other than numbness and pain, symptoms of meralgia paresthetica include pain on only one thigh or side of the body and sensitivity to touch.