There probably isn't a human being alive who isn't familiar with odd sensation of a hand or foot or limb falling asleep. That tingly, slightly numb feeling is annoying, to be sure, and can definitely derail you for a minute or two, but it's usually just the result of something completely innocent (like sitting in the same position for too long). In some cases, though, frequent pins and needles can be a sign of something more serious. In fact, if your hands and feet are always falling asleep, you might have one of several health issues.
When tingling in the hands, feet, or both becomes severe or starts happening all the time, WebMD explained, it can be a sign of nerve damage (particularly when it's accompanied by other symptoms like pain and itching). This is known as peripheral neuropathy "because it affects nerves distant from the brain and spinal cord," and it has a wide range of causes (from traumatic or repetitive stress injuries to infections to systemic diseases and even exposure to toxins). That's why it's important to get yourself checked out by a doctor if you find your hands and feet falling asleep on a regular basis. Hopefully it's NBD, but if there is something troubling going on, you'll want to start treating and managing that condition sooner rather than later. As WebMD put it, "The earlier the underlying cause of your tingling is identified and brought under control, the less likely you are to suffer potentially lifelong consequences."
Ranging from pins and needles in the feet and legs to problems with the digestive system, urinary tract, blood vessels, and heart, diabetic neuropathy is a type of nerve damage that can occur if you have diabetes, according to the Mayo Clinic.
That's because "high blood sugar (glucose) can injure nerves throughout your body," though the condition's progress can be slowed through blood sugar control and a healthy lifestyle. Peripheral neuropathy starting in the feet and legs (followed by the hands and arms) is the most common type of diabetic neuropathy, and symptoms include numbness, tingling, burning, and a reduced ability to feel pain or temperature changes (or, conversely, an increased sensitivity to pain).
2. Vitamin Deficiency
Not only is vitamin B12 deficiency common in the U.S., but a "clear link has been established between a lack of vitamin B12 and peripheral neuropathy," as the Foundation for Peripheral Neuropathy explained on its website:
"A lack of B12 damages the myelin sheath that surrounds and protect nerves. Without this protection, nerves cease to function properly and conditions such as peripheral neuropathy occur." Even relatively mild B12 deficiency can adversely affect the nervous system and the proper functioning of the brain, and this nerve damage can become "permanently debilitating" if the underlying condition is not recognized and treated.
3. Autoimmune Diseases
Autoimmune diseases such as Sjogren’s syndrome, lupus, and rheumatoid arthritis cause the immune system to attack the body’s own tissues, which can in turn lead to nerve damage, according to the National Institute of Neurological Disorders and Stroke:
"When the tissue surrounding nerves becomes inflamed, the inflammation can spread directly into nerve fibers. Over time, these chronic autoimmune conditions can destroy joints, organs, and connective tissues, making nerve fibers more vulnerable to compression injuries and entrapment."
4. Cancer Being Treated With Chemo
Neuropathy is a common side effect of some medications, according to the Foundation for Peripheral Neuropathy, particularly drugs used to treat cancer (known as chemo-induced PN):
"In some people, these medications may cause nerve damage that results in a loss of sensation or movement in part of the body." The good news is, peripheral neuropathy will usually go away if these drugs are changed or discontinued, or if the dose is reduced (though it can take anywhere from a few weeks to a few months for symptoms to subside.
A variety of both viral and bacterial infections and infectious diseases can also lead to nerve damage. The Mayo Clinic listed the following conditions as potential causes of neuropathy: Lyme disease, shingles, Epstein-Barr virus, hepatitis C, leprosy, diphtheria, and HIV (medicines used to treat HIV can also lead to temporary nerve damage, like chemo).
6. Hereditary Diseases
Sometimes, a hereditary condition is the cause for ongoing pins and needles, according to the Center for Peripheral Neuropathy. Charcot-Marie Tooth Disease, for example, is a progressive degeneration of the muscles in the foot, lower leg, hand, and forearm, while Hereditary Neuropathy with Liability to Pressure Palsies is a "hereditary disorder in which a fairly mild pressure or trauma to a single nerve" can result in episodes or periods of weakness and numbness. Also known to cause peripheral neuropathy is Ehlers-Danlos Syndrome, a rare genetic disorder of the connective tissue which has multiple neurological manifestations, and Multiple Sclerosis, a disease of the brain and spinal cord thought to be caused by a combination of genetic and environmental factors.
Remember, chances are you don't have anything to worry about, except that maybe you have a tendency to stay in the same position for too long. But if your extremities seem extremely sleepy on a regular basis, it can't hurt to get it checked out just in case.