Numbness in leg is a symptom directly related to the nerves that supply blood to the legs. When you sit cross-legged for a long period of time, blood is prevented from being distributed to your legs. Hence, when you get up, you may feel numbness, followed by a tingling sensation, and pain.
In some instances, the numbness in leg can be a recurring sensation. One possible cause is a condition known as Sciatica. Sciatica is characterized by pain in the lower back, buttocks, legs and feet. A person with this condition often feels numbness, pain, and weakness from the back to the lower limbs.
There are different types of medical conditions related to Sciatica such as Herniated Lumbar Disc or bulging in the lumbar spine; Lumbar Spinal Stenosis or narrowing of the spinal canal; Spondylolisthesis or the slippage of the vertebra and the spine; and the Piriformis Syndrome or the compression of the piriformis muscle- a muscle located in the lower part of the spine.
Injury is also a common cause of numbness of the limbs, particularly when the injured area or body part is located near the lower limbs or the leg itself. Sometimes, numbness in leg will occur immediately after the surgery or it may also develop a few months after the accident happened.
Pregnant women may also experience numbness in leg frequently especially during the last few months of pregnancy. This is because the womb presses on the sciatic nerve which brings about pain in the lower back and numbness, followed by a tingling sensation in the legs. However, the symptom is only temporary and will go away after the woman has gone through the delivery.
There are also mysterious causes which are often related to a neurological disorder. One example is a medical condition known as Restless Legs Syndrome (RLS) where the patient may feel episodes of numbness in leg, itching or burning sensation, and the irresistible urge to move the legs.
Another puzzling condition is called Transverse Myelitis which is an inflammation of one segment of the spinal cord. The cause of this condition remains to be a mystery until today. Anyone between the age of 20 to 40 may develop Transverse Myelitis. The symptoms usually include, urinary and bowel dysfunction, pain in the lower back, recurring headaches, loss of appetite, weakness of the upper limbs, fever, numbness in leg, and paralysis of the legs.