There are a variety of reasons that a person might experience leg weakness. When a person has weakness in his or her legs, he or she might have numbness, might have problems walking and often might lose his or her balance while trying to walk. In some mild cases, it might be caused by a person sitting on his or her legs in an uncomfortable position for an extended period of time. Some of other common causes of leg weakness are migraine headaches, Graves’ disease, multiple sclerosis and back injuries.
Migraines are classified as recurring severe headaches that might last for a couple of hours or several days. One of the signs of an oncoming migraine is numbness or weakness in the legs. The weakness might last for a short period of time, or it might last the entire time of the migraine. There are several factors, such as food or stress, that might trigger a migraine. It is not known why migraines affect some individuals more severely than others.
Graves’ disease is another one of the common causes of leg weakness. This disease is an autoimmune system disorder in which the body produces too much thyroid hormone. The overproduction of the thyroid hormone often might cause weakness in the large muscles of the legs. Other symptoms of Graves’ disease are weight loss, sweating and insomnia. After this disease has been diagnosed, it can be treated with an anti-thyroid prescription medication to return the thyroid hormone back to normal levels.
Another one of the common cause of weakness in the leg is multiple sclerosis (MS). This disease, which also is an autoimmune disease, affects the brain and nervous system because the body’s immune system attacks these systems. The nervous system is being attacked, so individuals with MS often experience numbness and weakness in the legs and have difficulty walking as the disease progresses. There is no known cure for MS, but medications can be used to slow the progression of the disease.
A back injury, which might cause damage to the sciatic nerve, also can be a cause for leg weakness. Many of the nerves in the back are connected to the nerves in the legs, and this is what causes the legs to become weak. In cases of severe back injuries, surgery and physical therapy might be needed in order to restore strength to both the back and leg muscles.