There are numerous causes of hand and foot tingling, and tingling in the extremities is often accompanied by numbness. According to the U.S. National Library of Medicine and the National Institutes of Health, numbness and tingling are abnormal sensations that may occur in any body part, but are especially common in the fingers, hands, feet, arms and legs. If the numbness and tingling are accompanied with muscle weakness, it's important to seek medical intervention as quickly as possible.
Thoracic Outlet Syndrome
Thoracic outlet syndrome or TOS can cause tingling in the hands. According to the National Institute of Neurological Disorders and Stroke (NINDS)—a division of the National Institutes of Health—TOS is an umbrella term that describes three related syndromes that cause symptoms in the neck, shoulder and arm. A person with TOS will experience nerve compression in their upper shoulder area, compression of the subclavian artery or vein and pain from unexplained causes. Both upper extremity nerve and blood vessel impingement may cause numbness, tingling, aching and heaviness along the underside of the hand and forearm. NINDS notes that TOS occurs more frequently in women, and that the onset of symptoms typically occurs between the ages of 20 and 50. TOS responds favorably to numerous types of conservative care methods, including postural exercises, stretching and manual soft tissue therapies.
Vitamin B12 Deficiency
Vitamin B12 deficiency can cause tingling in the hands and feet. According to the Merck Manuals website, severe vitamin B12 deficiency may cause tingling or a loss of sensation in the hands and feet, along with muscle weakness, blunted reflexes, difficulty walking, confusion and dementia. The Mayo Clinic website states that research has linked vitamin B12 deficiency with numerous other abnormal neurologic and psychiatric symptoms, including spasticity, incontinence, low blood pressure, vision problems, psychoses and mood disturbances. High risk populations for vitamin B12 deficiency include the following: strict vegetarians, the elderly, breast-fed infants and people with a greater need for vitamin B12, such as those who are pregnant or those with anemia, cancer and liver or kidney disease. The Mayo Clinic website notes that vitamin B12 can be administered orally, intramuscularly or intranasally to prevent or treat dietary vitamin B12 deficiency and hand and foot tingling.
Diabetes can cause hand and foot tingling and numbness. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)—a division of the National Institutes of Health—diabetes can cause neuropathies or nerve damage that results in pain, tingling or numbness in the hands, arms, feet and legs. NIDDK notes that, while diabetic-related nerve problems are common in the extremities, nerve problems can occur in every organ system, including the intestines, heart and sex organs. Symptoms associated with nerve damage, including hand and foot tingling, are often mild at first but progress over several years as nerve damage occurs. According to NIDDK, diabetics are more susceptible to nerve entrapment or compression syndromes, such as carpal tunnel syndrome (CTS). CTS may be a secondary cause of hand tingling in diabetics, and may occasionally cause hand muscle weakness or pain.