A Mysterious Signal
Many people feel numbness in their hands at some point in their lives. It can be a disturbing sensation, because most of us are aware that such numbness can be, at worst, a sign of serious or even life-threatening illness, such as a stroke, according to the Mayo Clinic. Along with numbness, one or both hands can experience a burning or tingling sensation or a sharp pain. In addition to being caused by a variety of medical conditions, numbness can be occupational (for instance, the result of a repetitive motion injury or carpal tunnel syndrome), a side effect of chemotherapy or radiation treatments, or related to alcoholism and tobacco use. Sedentary behavior or long periods of standing or sitting can produce numbness, and it can also be triggered by migraines or seizures, according to the National Institutes of Health. Attempts at home diagnosis are of very limited use because there is no way to know the cause of numbness without consulting a doctor. Even then, the diagnosis may not be immediately obvious without a long list of questions to narrow down possible underlying conditions. This may be followed by a selection of blood tests including complete blood count, electrolytes, levels of vitamins, thyroid function, and screens for toxicology or heavy metals. Imaging tests might include CT scans or MRI of the head and/or spine, angiogram or CT angiogram, X-rays of the hands or other areas affected by numbness, or ultrasound tests. Finally, nerve/muscle stimulation tests or nerve conduction studies may be ordered, as well as a "cold stimulation" test to determine whether susceptibility to cold, repetitive motion, or heavy vibration is causing the numbness. If a disorder of the central nervous system is suspected, a spinal tap may be necessary. While this is a daunting array of tests, ignoring recurrent or persistent occurrence of hand numbness or putting off medical consultation could be a serious mistake, the Mayo Clinic says.
Causes Requiring Early Medical Attention
According to the Mayo Clinic, the most common cause of hand numbness is the compression or irritation of a nerve branch that connects to some part of the arm or hand. However, it is important to make an early appointment with a doctor if numbness is intermittent, gradually worsens, or moves to other areas of the body. Some conditions that produce numbness include Type 2 diabetes, a deficiency of Vitamin B12, injury to the brachial plexus (a network of nerves running from the spine to the hand), Sjogren's syndrome, cervical osteoarthritis, amyloidosis (dementia), vasculitis, herpes zoster, ganglion cysts, syringomyelia, shingles, cholesterol buildup known as vascular claudication, lead poisoning, Raynaud's disease, an underperforming thyroid, and even multiple sclerosis, the Mayo Clinic says.
Causes Requiring Urgent Attention
Some possible indications that the numbness being caused by a very serious condition include sudden onset, numbness in the entire arm, general weakness or dizziness, blacking out, paralysis, loss of bladder control, severe headache, confusion and difficulty with speech. These symptoms can indicate a stroke (including mini-strokes called TIAs) or other life-threatening condition, and emergency medical care should be sought immediately, according to the Mayo Clinic. Some serious medical disorders causing numbness that require immediate attention include syphilis, spinal cord injury, Lyme disease, Guillain-Barre syndrome and related peripheral neuropathy, and HIV/AIDS.
