The Feeling of Pins & Needles Explained

What is Paresthesia?

Feeling an unmistakable sensation of “pins and needles” in the arms, hands, legs, or feet can be startling. We know it as a limb “falling asleep,” but the medical term is called paresthesia, a tingling, tickling, or prickling, usually felt in the extremities. While it can be bothersome, it is an extremely common and usually benign occurrence which is most often nothing for which to worry.

What Causes Paresthesia?

There are many catalysts that can cause paresthesia, the most common of which is temporary nerve or blood vessel compression. We tend to create this ourselves by sitting, lying, or leaning for a prolonged period in a position that cramps down on a nerve or vein, restricting blood flow to a body part. It starts out as a numb, heavy feeling, and turns into a lightweight, tingly response for 30 to 90 seconds in total. Our innate reaction is to shake the limb, which speeds and encourages blood flow again. The tingling comes when nerves resume functioning and communicate with the brain and spinal cord again, sending initially spotty signals to feel pain.

Tingling is not cause for concern unless it is frequently happening and for more than about 90 seconds at a time. It is not only wise but important to seek timely medical assessment for any persistent tickling or tingling in your hands, feet, or both. Smoking also restricts blood flow and can contribute to the sensation, which could be a sign of a greater problem. Like any other medical condition, the sooner your underlying cause is pinpointed, the more likely it can be brought under control, and long-term consequences can be prevented.

Causes of pins and needles

• Pressure on nerves (often caused from sitting, lying or leaning in a position for a prolonged period)
• Reduced blood supply
• Nerve damage
• Muscle atrophy
• Hyperventilation or excessive breathing
• Some medications
• Alcoholism - Alcoholics are more prone to suffer a thiamine or other vitamin deficiency which is most likely because of poor nutrition habits, which can lead to peripheral neuropathy. Alcoholism can also possibly cause nerve damage by itself. Some researchers refer to this as alcoholic neuropathy.
• Toxic substances (drugs, lead) - Toxins in heavy metals can cause paresthesia as a warning sign. Toxins like these include but are not limited to mercury, thallium, arsenic, lead, some industrial chemicals, certain medications, some antibiotic and antiviral medications, and especially chemotherapy used to treat lung cancer.

What can pins and needles be a sign of?

• Pinched nerve from carpal tunnel syndrome, vertebral subluxations, or misaligned joints
• Multiple sclerosis
• Underactive thyroid gland
• Transient ischemic attack
• Stroke
• Diabetes - Diabetics are also exceptionally vulnerable to suffering chronic paresthesia. About two-thirds of people with diabetes have some form of nerve damage. High blood sugar can damage nerve ending fibers, usually in the hands and feet, although this can affect any area of the body and can be crippling.
• Vitamin deficiencies- Vitamins B1, B6, B12, E, and niacin are crucial to a well-functioning nervous system. For example, a B12 deficiency can cause pernicious anemia, a substantial cause of peripheral neuropathy. On the other hand, too much vitamin B6 can cause pins and needles in the hands and feet.
• Infection or autoimmune diseases - Some infections and autoimmune diseases commonly provoke tingling as well. Shingles, cytomegalovirus, Epstein-Barr, Lyme disease, herpes simplex, and HIV/AIDS fall under the umbrella of trigger infections. Autoimmune diseases can include lupus, rheumatoid arthritis, and Guillain-Barre syndrome. 

When to Worry About Feeling Pins and Needles

If you opt to seek professional care for your tingling appendages, your physician will do a standard physical exam. From there, they will record and evaluate an extensive medical history addressing your symptoms, lifestyle stress, alcohol intake, toxic exposure, risk of infectious diseases, and of course family history of any neurological diseases.

He or she also may perform additional tests including blood tests, spinal fluid analysis, nerve conduction velocity, or an electromyogram (EMG). These can include tests to detect diabetes, vitamin deficiencies, liver or kidney dysfunction, other metabolic disorders and signs of atypical immune system function.

If you still aren’t quite sure whether you’re a candidate to seek medical attention for paresthesia symptoms, ask yourself these questions:

• Does the numb or prickly sensation tend to last longer than 90 seconds?
• Does this frequently happen and without apparent reason? Does it come on spontaneously?
• Does the sensation remain the same, even if I shift my sitting or lying position?
• Does this commonly disrupt my sleep or quality of life in any way?

If you answered yes to any of these questions, you might need to schedule a consultation with a neurologist. Talk to you primary care doctor about your symptoms.