Numbness is when you can't feel anything in part of your body, usually a patch of skin. Pins and needles are a tingling or prickling sensation that is often felt in hands or feet. Most numbness or pins and needles is due to pressure on nerves or the blood vessels that supply nerves. This often happens after you've been in an awkward position, like sitting cross-legged or may be the sign of a trapped nerve. Occasionally, it may be the sign of a more serious underlying problem such as diabetes.
The most common causes are mentioned below.
What are numbness/pins and needles?
Numbness/pins and needles occur when you lose normal sensation in an area of the body. This happens because pressure cuts off the blood supply to nerves that carry messages about sensation to the brain. Numbness is when you don't feel anything; if a doctor used a pin to prick your skin, it wouldn't feel sharp. When you experience pins and needles, have an abnormal, usually unpleasant feeling in a part of your body. It may feel like lots of tiny pinpricks, tingling or shooting pains that travel down an arm or leg, or affect just one toe or both feet.
Who is affected by numbness/pins and needles?
You can get numbness/pins and needles by putting pressure on a part of your body, like wearing tight shoes or sitting on your foot. People with back pain, diabetics or people who use vibrating tools are more prone to develop the problem.
What problems can cause numbness and pins and needles?
This list does not include all the possible causes of numbness/pins and needles but lists some of the more common causes including:
Wearing tight shoes or sitting on your foot can give you a numb foot or leg or cause pins and needles. This kind of numbness has an obvious cause, gets better when the pressure is removed and doesn't cause any further problems.
Numbness or pins and needles can also be due to a trapped nerve. A slipped disc or back problem can put pressure on a nerve that travels from your back, down your leg and into your toes. A trapped nerve in the neck can also cause numbness or pins and needles anywhere from your neck, down your arms and into your fingers. Carpal tunnel syndrome is a trapped nerve at the wrist, giving you pins and needles and pain in the hand, and loss of grip.
Diabetes can damage small blood vessels that supply nerves in fingers and toes. This can cause pins and needles, pain or numbness in the hands and feet (peripheral neuropathy). Being unable to feel anything in your hands and feet can be dangerous, as you may stumble, drop things or not realise when you are touching something hot.
Damage to nerve endings in fingers or toes can be the result of an injury. People who use vibrating tools a lot may also develop nerve damage and may experience pins and needles.
Some medicines can cause nerve damage. It is usually reversible when the medicine is stopped. The medicines include some chemotherapy medicines used to treat breast cancer and lymphoma, antiretrovirals used to treat HIV/AIDS, and the antibiotic metronidazole.
Diseases that damage nerves
Many conditions can damage the nervous system and cause areas of numbness or pins and needles. These include stroke, multiple sclerosis and brain tumours. These conditions are serious but relatively rare and will all cause other symptoms in addition to the numbness/pins and needles.
Alcohol abuse can damage nerves.
Vitamin B12 deficiency is common among very elderly people, vegans and people with a condition called pernicious anaemia. The lack of vitamin B12 causes anaemia and nerve damage.
What investigations might be advised?
The doctor will want to know more about the length of the periods of numbness/pins and needles. Is there any obvious cause? Have you started new medication? Do you drink a lot of alcohol? Do you have diabetes? These details will help the doctor to make a diagnosis. Your doctor will examine you. They will check your heart, including your blood pressure and pulses in your wrists and feet. Your nervous system will be checked and you may be asked whether you can feel a pinprick or other sensations in your limbs. You may be asked to have a blood test to check for diabetes, anaemia and vitamin B12 levels. Further tests of your heart and nervous system may be necessary.
What treatments may be offered?
Treatment will depend on the likely cause of your numbness/pins and needles. You may be asked to keep a diary of the circumstances in which they happened. Most cases will be managed by your GP but you may be referred to a hospital for further investigation and treatment.
What can I do if I feel numbness/pins and needles?
- Loosen any tight clothing/shoes.
- Get up and shake the limb if you have been sitting/leaning on it for a long time.
- Minimise neck/back problems by avoiding lifting heavy weights, avoid repetitive movements, take regular breaks at work, avoid poor posture, consider doing yoga or Pilates.
- Control diabetes, if you have it, with diet, medication and regular check-ups.
- Avoid excess alcohol.
- Avoid vitamin B12 deficiency by eating a mixed diet or have a blood test to check whether you need supplements.
- See your doctor soon if you have signs of a neurological disease (worsening loss of power or sensation in part of the body, difficulty walking, falls)
- See your GP if the problem recurs, has no obvious cause or doesn't fully recover within a few minutes.
Driving is not a problem for simple numbness/pins and needles but restrictions apply if the situation is more complicated or if diagnosis is less clear.
If in doubt, contact the Driver and Vehicle Licensing Agency (DVLA).
What should I do next?
You should call an ambulance if you notice you have a loss of power down one side of your body (a possible stroke). If the attacks of numbness/pins and needles recur or you do not make a complete recovery, you should also seek urgent medical attention. If you have lots of attacks, or you hurt yourself because of the numbness, your GP may want you to see a specialist. In all other cases, you should see your GP.
How can I avoid numbness/pins and needles?
You will need to find the underlying cause and try to address it if possible. Diabetes is the most common cause of persistent numbness/pins and needles. Pressure on nerves due to back and neck problems is also very common.
What is the outlook (prognosis)?
This depends on the underlying cause. Persistent numbness of the feet can lead to falls and numbness of the hands; this can affect your grip and make you prone to burns and injury.
Dr Ann Robinson
Dr Ann Robinson
Dr Hayley Willacy