Pins & Needles – Tingling Sensation in the Hands/Feet
We all tend to experience at some point of time tingling sensation in the hands or feet and we call it pins and needles since we get the sensation of hundreds of tinypointed object passing over the skin again and again. One would feel a bit of numbness on the skin besides the sensations of those pins and needles.
It could be little uncomfortable to place the weight of the body on your foot when it tends to fall asleep and though not painful it is also not pleasant either. However after a few minutes when one shakes the affected limb, the sharp piercing sensation tends to disappear. The sensation is referred as `paresthesia’ and the harmless sensation is known as temporary paresthesia.
What really happens beneath the tingling skin is that there are nerves throughout the body, biological superhighways which relay information between the brain and the entire body. If too much pressure is placed on one of the limbs, you could be momentarily pinching the nerve which tends to run through them. Besides that, you could also be putting a little more pressure on the blood vessels supplying those nerves just the way a hampering garden hose tends to prevent the flow of water.
Brain Deprived of Information from Nerves
The outcome is that the brain is deprived of the information expected from this bundle of nerves since the nerves themselves are refrained from receiving the oxygenated blood needed from the heart. When the pressure tends to get relieved, blood floods back in the limbs with the nerves firing information to and from the brain.Some experiments conducted in 1930s and 1940s provided the understanding to the researchers on the progression of the sensation.
It is easy to put a limb to sleep by using a blood pressure cuff which tends to squeeze the person’s limb to a higher pressure that their systolic blood pressure which was what the Oxford University researcher had done in 1946. Beginning a minute or two after applying the pressure and lasting for three to four minutes, they felt a sensation called `compression tingling’ The participants described it as faint comfortable soda water sensation or buzzing or a fine light tingle while others felt as if they had some ants running up and down within their skin.
Velvety Numbness/Release Pricking
The second stage that tends to begin 10 minutes later is known as velvety numbness which lasts as long as the pressure on the nerve of the limb and blood supply remains. The pressure when released is the third state which is known as `release pricking’. This part is generally referred to as `pins and needles’. Release pricking usually tends to be more painful than the first two stages though the emotional aspect of the experience seems to be described often as curiosity or interest.
The sensation ultimately disappears though people are unable to identify at what point the sensation on their skin returns to normal. However, not all pins and needles seem to be of the temporary range. Chronic paresthesia could take place as part of various neurological disorders or after a certain traumatic damage of nerve such as a bad burn. Paresthesia could also take place after the administration of local anaesthetic medications during dental process. Though these are rare incidences, it is not known why this tend to occur.