Numbness in hands and feet: causes, tests and when to see a GP

Numbness, tingling and pins and needles are sensory symptoms, signals that the nerves carrying sensation from your hands and feet are not working normally. The NHS describes pins and needles as a pricking, tingling or numbness sensation. Everyone can get it, and when it comes from lying on an arm or crossing your legs, it settles as soon as the weight is taken off and the blood supply returns.

When the sensation is ongoing, affects both hands, both feet or all four limbs, or is accompanied by pain, weakness or loss of balance, the possible explanation changes. The NHS describes peripheral neuropathy as damage to the nerves in the extremities such as the hands, feet and arms, with symptoms depending on which nerves are affected.

The causes depend on the pattern of symptoms. The NHS gives the following guide and stresses that you should not self-diagnose.

• Treatments such as chemotherapy.

• Some medicines, such as HIV medicine, medicine to prevent seizures or some antibiotics.

• Toxic substances such as lead or radiation.

• Poor diet, including vitamin B12 deficiency.

• A trapped nerve in the back or neck, or nerve damage after injury or illness.

• Drinking too much alcohol.

Two causes deserve special mention because they are common and treatable. The NHS says diabetes, both type 1 and type 2, is the most common cause of peripheral neuropathy in the UK, because high blood sugar over time can damage nerves. It lists feeling very tired, peeing more than usual, feeling thirsty all the time and losing weight without trying as the most common symptoms of type 2 diabetes, and says not everyone has symptoms, so a blood test is needed. People with diabetes are recommended to have regular check-ups.

The NHS says vitamin B12 deficiency can cause neurological symptoms including numbness, muscle weakness, pins and needles, problems with balance and coordination and psychological changes. It says that although many symptoms improve with treatment, some problems can be irreversible if left untreated, and that the longer the condition goes untreated, the higher the chance of permanent damage. This is why a GP often checks B12 and blood sugar early.

The NHS says a GP will ask about your symptoms and examine the affected area, which may include testing sensation, strength and reflexes. They may arrange blood tests, especially to check for diabetes or vitamin B12 deficiency. If you are taking a medicine known to cause peripheral neuropathy, the GP may temporarily stop or reduce the dose to see whether symptoms improve.

Some people are referred to a neurologist for further tests. The NHS lists a nerve conduction test, where electrodes on the skin measure the speed and strength of nerve signals, and electromyography (EMG), where a small needle measures the electrical activity of muscles, usually carried out together. Other investigations include more blood tests, a lumbar puncture, occasionally a nerve biopsy, and scans such as X-ray, CT or MRI to look for an underlying cause.

The NHS says treatment depends on the symptoms and underlying cause, and that not all causes can be treated. If you have diabetes, it may help to gain better control of blood sugar, stop smoking and cut down on alcohol. Nerve pain may be treated with prescribed neuropathic pain medicines, as standard painkillers often do not work. Muscle weakness may involve physiotherapy and walking aids.

The outlook varies with the cause and with which nerves are damaged. The NHS says some cases may improve over time if the underlying cause is treated, while in others the damage may be permanent or may gradually worsen. If the cause is not treated there is a risk of serious complications, such as a foot ulcer that becomes infected.

The NHS identifies a cut or ulcer on your foot that is not getting better as a reason to see a GP, which matters particularly if sensation in the feet is reduced.

Sudden numbness needs different handling from slow-onset tingling. The NHS stroke symptoms page lists weakness or numbness down one side of the body, face drooping, arm weakness and slurred speech, and says to call 999 straight away, even if the symptoms stop after a short time. Use the FAST test (face, arms, speech, time to call 999).

The NHS also recommends seeing a GP promptly for early symptoms of peripheral neuropathy: pain, tingling or loss of sensation in the feet, loss of balance or weakness, or a cut or ulcer on your foot that is not getting better.