Some neurological causes of ongoing numbness and tingling in the leg include multiple sclerosis, nerve damage, a herniated disc or tarsal tunnel syndrome, according to Healthline. Other causes include fibromyalgia, diabetes, peripheral artery disease and vitamin B-12 deficiency. If a person experiences numbness and tingling that is not the result of an obvious cause, such as sitting too long or medication, he should seek medical attention to rule out a more serious cause.
Multiple sclerosis is a neurological autoimmune disease that causes symptoms such as numbness, muscle spasms, difficulty moving the extremities and loss of balance, explains Healthline. Nerve damage can be the result of substance abuse, injury or certain health conditions, and symptoms include numbness, tingling and pricking sensations throughout the body.
A herniated disc causes pinching of the protective cushioning between the bones of the spine, and pain, numbness or tingling in the back or extremities is a common symptom. Tarsal tunnel syndrome is the result of trauma or excessive pressure on the tibial nerve in the leg and may cause numbness, tingling, pain, weakness or a burning sensation in the feet. Diabetes, peripheral artery disease and a vitamin B-12 deficiency are also possible causes of nerve damage that may lead to symptoms such as numbness, burning, weakness or loss of sensation.