Nerve pain in the legs is frequently caused by injury to the peripheral nervous system. Sometimes nerves become entrapped or compressed, causing chronic pain and numbness. A common cause of nerve pain in the legs is pressure on the spinal roots of the sciatic nerve due to vertebral disc herniation. Peripheral neuropathies, a complication of diabetes, lead to progressive and painful loss of neural control of the legs and feet.
While not a disease in its own right, nerve pain in the legs is usually a symptom of another underlying disorder. Important among these are lower spine problems, since many nerves in the leg have spinal roots. Neural pain is called a neuralgia. A diagnosis must first establish that a nerve is damaged in order to rule out leg pain caused by non-neurological conditions like varicose veins or fibromyalgia. Treatment varies widely depending on the cause of the neuralgia, although management of symptoms often involves anti-inflammatory drugs and pain medication.
Traumatic injury to the leg can cause neurological damage resulting in chronic pain. So can entrapment, which occurs when a nerve leading to the leg gets compressed at a location where it passes through a tight space. The resulting damage is called an entrapment neuropathy. The obdurator nerve of the thigh can be entrapped at the point where it leaves the pelvis and enters the leg, just as the femoral cutaneous nerve can be pinched, causing chronic pain in the thigh. Morton's neuroma is the inflammation resulting from a compressed plantar nerve in the foot, and is often caused by constrictive or unsupported shoes.
Sciatic nerve pain in the legs is often the result of a vertebral disc that slipped from its place in the spinal column and put pressure on the spinal cord. When the pressure is applied to the lumbar or sacral spinal cord, pain is referred down through the sciatic nerves that run through the buttocks and down the legs. Typically the aching begins in the lower back and radiates down one leg. The onset of symptoms may be acute if caused by injury or sudden disc herniation, or gradual if the pressure on the spine increases incrementally.
Nerve pain in the legs is an important sign of a peripheral neuropathy. Often striking the foot before the leg, both motor and sensory nerves are affected, and neuropathies combine pain and tingling with difficulty moving. Neuropathy develops in many different diseases, but the most common source is a complication of uncontrolled diabetes mellitus. Unlike sciatica or pinched nerves, where relieving pressure diminishes pain, neuropathic neuralgia is often accompanied by permanent loss of function. For this reason, treatment of the underlying diabetic symptoms is essential.