Pins and needles and numbness: when to take it seriously
Pins and needles can be one of those strange sensations that appears out of nowhere. Your foot goes numb after you've been sitting awkwardly, your hand tingles after sleeping on your arm or your leg feels prickly when you stand up.
Usually, the sensation passes within a few minutes once you change position. But persistent or recurring numbness is different. It can have many possible causes, from a trapped nerve to vitamin B12 deficiency, diabetes or certain medicines.
The pattern matters. Where the sensation occurs, how long it lasts and whether you have other symptoms can all help provide clues about what's going on.
When pins and needles are usually nothing to worry about
Most people know the familiar feeling of a foot or hand "going to sleep".
This happens when pressure temporarily affects the blood supply to the nerves. Once you move and take the pressure off, the sensation normally fades within a few minutes.
You may notice it after:
- Sitting with your legs crossed for a long time
- Sleeping in an awkward position
- Leaning on your elbow
- Staying in one position for too long
Occasional pins and needles that has an obvious explanation and disappears quickly usually isn't a cause for concern.
It's when the sensation becomes a regular visitor that it's worth paying more attention.
The pattern can tell you more than the sensation itself
Numbness isn't a diagnosis. It's a symptom that can have many different explanations.
For example, tingling in the fingers may be linked to pressure on a nerve in the wrist, such as with carpal tunnel syndrome. Numbness that travels from the back down the leg can occur with sciatica. Persistent tingling in the hands or feet can have several possible causes, including peripheral neuropathy.
Think about:
- Where is it happening? One hand, both feet, one side of the body or several areas?
- How long does it last? Seconds, minutes or most of the day?
- How often does it happen? Occasionally or increasingly regularly?
- Is it getting worse? Is the area becoming more numb or less sensitive?
- What else is happening? Are you experiencing weakness, pain, balance problems or changes in your vision? These details can help a healthcare professional decide whether you need further investigation.
Common reasons for ongoing numbness
There are plenty of possible explanations for persistent pins and needles, and many are manageable once the cause is understood.
Trapped or compressed nerves
Pressure on a nerve can cause tingling, numbness or pain in the area supplied by that nerve.
Carpal tunnel syndrome is one example. Pressure on a nerve in the wrist can cause symptoms in the hand and fingers, often becoming more noticeable at night.
Nerves can also become irritated in the neck or back, sometimes causing symptoms that travel into an arm or leg.
Vitamin B12 deficiency
Vitamin B12 helps keep the nervous system healthy. A deficiency can affect the nerves and may cause symptoms including numbness or pins and needles.
NICE recommends considering vitamin B12 deficiency among the possible causes when adults have persistent altered sensation in the hands or feet.
A blood test can measure your vitamin B12 levels and help establish whether deficiency could be part of the picture.
Blood sugar and diabetes
Persistent numbness or tingling in the feet or hands can sometimes be associated with diabetes. Over time, high blood sugar can damage the nerves, causing a condition known as peripheral neuropathy.
This is one reason blood glucose can be useful to check when someone has ongoing altered sensation.
An HbA1c blood test gives an indication of your average blood glucose levels over the previous two to three months and is commonly used when checking for type 2 diabetes.
Thyroid and other health factors
NICE guidance recommends considering thyroid function, kidney function and other factors when persistent altered sensation suggests peripheral neuropathy.
Some medicines, alcohol, previous injuries and other health conditions can also affect the nerves. This is why there isn't one blood test that can explain every case of numbness.
Blood tests that may provide useful clues
If your symptoms are persistent or keep returning, a healthcare professional may recommend tests based on your symptoms and medical history. These can include:
| Test | What it can show |
|---|---|
| Vitamin B12 | Whether you have enough vitamin B12, which is important for healthy nerves |
| HbA1c | Your average blood glucose levels |
| Thyroid function | How well your thyroid is working |
| Kidney function | How well your kidneys are filtering waste from your blood |
| Folate | Your level of folate, which is important for healthy blood cells and other body processes |
| Full blood count | Information about your red and white blood cells and platelets |
The right tests depend on the individual. Blood tests are only one part of investigating numbness. A healthcare professional may also examine your strength, reflexes, sensation and balance and ask about your medication, diet and medical history.
Signs that deserve prompt attention
Most pins and needles isn't an emergency. There are certain patterns, however, where you shouldn't wait and see if they pass.
Sudden numbness or weakness affecting one side of your face or body, particularly alongside problems with speech, should be treated as an emergency. Call 999. These can be signs of a stroke or transient ischaemic attack (TIA).
You should also seek urgent medical help if numbness is accompanied by symptoms such as:
- Sudden weakness or difficulty moving
- Problems speaking or understanding speech
- Sudden changes to your vision
- Significant difficulty walking or keeping your balance
- Loss of bladder or bowel control
- Severe or rapidly worsening symptoms If you're unsure how urgently you need help, NHS 111 can assess your symptoms and advise you on the appropriate next step.
For symptoms that aren't sudden or severe but keep coming back or last a long time, arrange an appointment with your GP. The NHS recommends speaking to a GP if you have persistent or recurring pins and needles.
What can a Bluecrest Health Assessment tell you?
If numbness or pins and needles is part of a wider change in how you're feeling, checking several health markers can provide useful information.
A Bluecrest Health Assessment can include a range of physical measurements and blood tests, depending on the package you choose. These can cover areas such as blood pressure, blood sugar, cholesterol, liver and kidney function, iron and other health markers.
Bluecrest also offers individual tests, including tests covering vitamin B12, folate, thyroid function and vitamin and mineral levels.
Results are presented using a straightforward green, amber and red flag system, making it easier to see which results are within the expected range and which may need some attention.
A Health Assessment isn't designed to diagnose the cause of numbness or pins and needles. If you're experiencing persistent or unexplained symptoms, it's important to discuss them with an appropriate healthcare professional. Your results can provide additional information to consider alongside your symptoms and medical history.
Anna Jones
Chief Nursing Officer, BluecrestGraham Jones
Medical Writer
