Numbness and tingling in the arms and legs are abnormal sensations that result from disorders of a nerve or nerves. There are many different possibilities as to the cause of these symptoms. Most of the time the cause is not serious, but certain associated signs and symptoms can signal the need to see your doctor.
A major cause of numbness and tingling is peripheral neuropathy. This refers to an abnormality of the nerves outside the spinal canal. Several causes of neuropathy exist, including, but not limited to diabetes, peripheral nerve entrapment, vitamin and mineral deficiencies, inflammatory or rheumatologic disorders, alcoholism, kidney failure, circulatory issues and damage from chemotherapy and radiation. In diabetics, the numbness and tingling is often accompanied by increased thirst, hunger, and urination. The most common nerve entrapment is carpal tunnel syndrome which affects the hand and wrist. Increased risk of carpal tunnel syndrome is noted in people who do repetitive wrist activity such as typing or cutting hair. Vitamin B-12 and folate are common vitamin deficiencies and can be associated with weakness from anemia, paleness, loss of appetite, and sore tongue and mouth. Long term excessive alcohol drinking can cause numbness and tingling and is usually associated with a wide-based gait. Certain rheumatologic or endocrine conditions that can cause neuropathy include rheumatoid arthritis, amyloidosis, fibromyalgia, thyroid problems, or Raynaud’s phenomenon. Neurologic neuropathies (such as chronic inflammatory demyelinating polyneuropathy) are typically associated with weakness in the arms or legs. Sciatica is a condition where the sciatic nerve is affected after exiting the spinal cord as it passes through the hip or buttock area. This is commonly associated with leg pain and/or back pain.
Disorders of the brain and spinal cord also commonly cause numbness and tingling. Problems in the cervical spine can result in symmetrical arm and leg numbness and possible paralysis of the arms and legs. Thoracic (mid back) problems affect the trunk and legs. Lumbosacral (low back and tailbone) conditions affect the hips and legs. Multiple Sclerosis is an autoimmune disorder which can cause these symptoms, but these will rarely occur in a symmetrical pattern. Other spinal cord problems such as tumors or cysts can be associated with pain, weakness, clumsiness, or bowel or bladder problems.
Vascular or circulatory problems leading to lack of blood supply to an area can cause numbness and tingling. This will commonly accompany blue or red discoloration, paleness or cold and painful sensation in the area.
While the potential causes of these symptoms are quite varied, certain causes are obviously of greater concern than others. Numbness and tingling that is associated with weakness, paralysis, or loss of bladder or bowel control warrant emergent evaluation and treatment by a healthcare professional. Also, any symptoms of confusion, vision or speech changes, weakness, or loss of consciousness should prompt a visit to a local emergency department. Numbness and tingling associated with neck or back pain, arm or leg pain, muscle spasms, or rash require a call or visit to your physician but are less urgent in nature. Obtaining a proper history and physical from a physician, as well as diagnostic testing and procedures, are necessary to make a correct diagnosis and implement proper treatment. If any of these symptoms are experienced and persist despite change in position or activity, please consider evaluation with your doctor for appropriate care.