The medical name for pins and needles is paraesthesia, and there are a variety of possible causes.

Paraesthesia is a sign that sensory nerves in the area of the tingly sensation are being irritated (rather than motor nerves which control movement). This irritation may be the result of disease or damage to the nerves themselves, damage to the blood supply, or disease of the surrounding tissues, such as arthritis, which ultimately affects the nerves.

Pins and needles become more common as a complaint as people get older simply because it becomes increasingly likely that some sort of disease may irritate the nerves. One of the most common causes in older people is poor blood supply to the limbs because of atherosclerosis or hardening of the arteries - a condition which millions of people in the developed world suffer.

Another common problem among the elderly is arthritis, which can interfere with both nerves and blood supply.

The most likely answer to your mother's symptoms is that it isn't serious and simply reflects some common changes of ageing. However, there are some causes that need to be ruled out and your mother should get her own doctor to check it out.

Nerve damage

Almost any condition that can damage nerves may cause pins and needles. In these cases the tingling can be extremely unpleasant, with a raw burning character.

Although unlikely in your mother, in younger people multiple sclerosis often begins with a prolonged episode of pins and needles for which no other cause can be found.

Other causes include:

• Vitamin deficiencies: although few people in the UK suffer from severe vitamin deficiencies, the elderly are prone to a poor diet and minor deficiencies. Check that your mother has a balanced diet and consider vitamin supplements.
• Metabolic disorders (ranging from diabetes to changes in blood chemistry that occur during a panic attack. Both these examples are common causes of tingling in the fingers).
• Poisoning, especially with heavy metals.
• Infections.

Poor blood supply

Irritation of the nerves may result when their blood supply is reduced or cut off. Either by chronic disease such as atherosclerosis, intermittently (for example, in a condition called Raynaud's phenomenon where the artery goes into spasm) or acutely by sudden compression of the arteries (a classic problem is when someone gets drunk and falls asleep with their arm hanging over the edge of a chair).

Tingling is a sign that the nerve is still alive, if under threat. When the nerve dies the tingling should stop. So it may be a good warning sign to take action.

This article was last medically reviewed by Dr Trisha Macnair in June 2008