An estimated 30 million Americans have some form of neuropathy. Depending on the cause and patient, symptoms of neuropathy can include pain; altered, increased, or reduced sensation; tingling; pins and needles sensations; burning; increased sensitivity to touch; muscle weakness or wasting; paralysis; dysfunction in organs or glands; or impairment to urination and sexual function. (2,3,4) There are more than 100 types of neuropathy. Among the more common causes, and their risk factors, are: Matthew Villani, DPM, a podiatry specialist at HCA Florida Lake Monroe Hospital in Sanford, Florida, explains that these symptoms arise because “the nerves are being encapsulated by the sugar, which causes the conductive properties of the nerves to slow down or be altered, so that the electrical impulses to the nerves aren’t functioning properly.” (5)
3. Age
Neuropathy is present in 2.4 percent of the general population. But prevalence increases with age due to the increase in chronic disease risk as people get older. Eight percent of people ages 55 and older have some form of polyneuropathy (meaning multiple nerves are involved, the most common form) according to a frequently cited study. (8,9) With Lyme disease, up to 12 percent of people develop neurological symptoms, especially neuropathy involving the face. (13,14,15) Vitamin B12 deficiency, which is prevalent in 10 to 15 percent of people older than age 60, has been linked to neuropathy. The deficiency causes damage to the myelin sheaths that surround and protect nerves. Chronic use of the type 2 diabetes drug metformin (Glucophage) is linked to vitamin B12 deficiency, so if you are taking the medication, your levels of the nutrient should be monitored by a physician. (16,17,18) For instance, says Dr. Latov, “too much B6 can be toxic to the nerves. The normal requirement is less than 2 milligrams (mg) a day, yet many B6 supplements are 100 mg or more. B6 is also an additive to all sorts of packaged foods.” He advises having your blood levels monitored if you are taking a B6 supplement. (19) “Some people eat lots of seafood in their diet because they think it’s healthy, but it can also contain lots of mercury,” Latov says. (20) “In our center, we see people with very high levels of mercury, which can cause neuropathy. Brown rice can have high arsenic levels, and that can cause neuropathy, too.” (21,22) Repetitive stress from work, hobbies, or sports can also put one at risk for neuropathy. For instance, carpal tunnel syndrome, which arises from repeated pressure on nerves and tendons in the hands, can result in burning, tingling, or numbness in the palms and along the fingers. The condition usually affects people between ages 40 and 60, and is more common in women than in men. (23)
11. Your Genes
Certain forms of neuropathy can be inherited and passed down from parent to child. Often hereditary neuropathies affect the extremities, and can lead to muscle atrophy and weakness, as well as loss of sensation. They can be diagnosed through blood tests for genetic testing, nerve conduction tests, and biopsies of nerves or muscles. The most common hereditary neuropathy is Charcot-Marie-Tooth disease, which affects an estimated 126,000 people in the United States. It involves motor and sensory nerves, and symptoms can include foot deformities, such as high arches and hammertoes, due to weakness of the small muscles in the feet; difficulty lifting the foot or holding it in a horizontal position; decreased sensation in the foot or leg; an unsteady gait; difficulty with balance; and problems with hand coordination. Among the complications that may result from this disease are sprains and fractures in the ankles, feet, and legs. Onset of Charcot-Marie-Tooth disease is generally between mid-childhood and early adulthood, and although it is progressive, the disease is not considered to be fatal. (25,26,27,28) Hereditary neuropathy with liability to pressure palsies (HNPP) is another common form of hereditary neuropathy, affecting 2 to 5 per 100,000 people in the United States. People with HNPP are unusually sensitive to pressure, particularly in their wrists, elbows, and knees. They may have recurrent episodes of numbness, tingling, and loss of muscle function in the area associated with an affected nerve, lasting anywhere from several minutes to several months. (29,30)