Chronic paresthesia indicates a problem with the functioning of neurons or poor circulation.
In older individuals, paresthesia is often the result of poor circulation in the limbs (such as in peripheral vascular disease), most often caused by atherosclerosis, the buildup of plaque within artery walls, over decades, with eventual plaque ruptures, internal clots over the ruptures and subsequent clot healing but leaving behind narrowing of the artery openings or closure, both locally and in downstream smaller branches. Without a proper supply of blood and nutrients, nerve cells can no longer adequately send signals to the brain. Because of this, paresthesia can also be a symptom of vitamin deficiency and malnutrition, as well as metabolic disorders like diabetes, hypothyroidism, and hypoparathyroidism. It can also be a symptom of mercury poisoning.
Irritation to the nerve can also come from inflammation to the tissue. Joint conditions such as rheumatoid arthritis, psoriatic arthritis, and carpal tunnel syndrome are common sources of paresthesia. Nerves below the head may be compressed where chronic neck and spine problems exist and can be caused by, among other things, muscle cramps that may be a result of clinical anxiety or excessive mental stress,[citation needed] bone disease, poor posture, unsafe heavy lifting practices or physical trauma such as whiplash. Paresthesia can also be caused simply by putting pressure on a nerve by applying weight (or pressure) to the limb for extended periods of time.
Another cause of paresthesia may be direct damage to the nerves themselves, i.e., neuropathy, which itself can stem from injury or infection such as frostbite or Lyme disease, or may be indicative of a current neurological disorder. Neuropathy is also a side effect of some chemotherapies (see Chemotherapy-induced peripheral neuropathy).[3] Benzodiazepine withdrawal may also cause paresthesia as the drug removal leaves the GABA receptors stripped bare and possibly malformed. Chronic paresthesia can sometimes be symptomatic of serious conditions, such as a transient ischemic attack, or autoimmune diseases such as multiple sclerosis or lupus erythematosus.[citation needed] Exposure to environmental toxins, chemicals used in water treatment and fluoroquinolones can also cause paresthesia.[4] Stroke survivors and those with Traumatic Brain Injury (TBI) may experience paresthesia from damage to the central nervous system.
The Varicella zoster virus disease (shingles) can attack nerves causing numbness instead of pain commonly associated with shingles. A diagnostic evaluation by a medical doctor is necessary to rule these out.[clarification needed]
Acroparesthesia Edit
Acroparesthesia is severe pain in the extremities, and may be caused by Fabry disease, a type of sphingolipidosis.[5]
