Causes of Hand Numbness

Overview

Hand numbness, also known as ‘paresthesia’, is the loss of feeling in your hands or fingers and can have several causes. Numbness itself is not a condition but a symptom of some other disease. Therefore, the best way to treat it is to treat the underlying cause. For the cause to be diagnosed correctly, you have to observe how often you experience the numbness, how long it stays and what other symptoms accompany it. Another symptom that follows numbness is a tingling feeling in your hands (referred to as ‘pins and needles’). 

Is numbness in your hands serious?

Although numbness in your hands is not serious, it may be a symptom of a serious disease, such as a heart attack or stroke if accompanied by tingling. You should seek immediate medical care if you also feel the following symptoms along with numbness and tingling:¹

• Slurred speech
• Weakness
• Blurry vision
• Severe headache
• Chest pain
• Dizziness
• Abnormal heart rhythm

Neurological causes of hand numbness

Carpal tunnel syndrome (CTS)

Carpal tunnel syndrome is the most common cause of hand numbness. CTS is a condition that happens when there is pressure on the median nerve found in your wrist. As a result, you may get less sensation from your hands or impair your ability to control them, leading to the symptoms below. You can diagnose and treat CTS yourself by looking for the following symptoms.

Symptoms

The symptoms include pain and tingling (pins and needles) in your hands and fingers, numb hands and difficulty in gripping objects.²

Causes

CTS develops when your carpal tunnel becomes swollen and presses onto the median nerve in your wrist. You are more at risk of getting CTS if you are pregnant or overweight, have arthritis or diabetes, perform activities that require frequent bending of your wrist (e.g. using vibrating tools), have a previous wrist injury, or a family history of CTS.²

Treatment

Carpal tunnel syndrome gets better by itself within months. Self-management involves wearing a wrist splint, stopping activities that require you to bend your wrist or grip hard (for instance playing an instrument), taking painkillers (e.g., paracetamol, ibuprofen), and doing hand exercises. If your symptoms get worse, seek medical help. The doctor can give you a steroid injection, but if the syndrome relapses after a few months, surgery is required.³ The procedure involves injecting a local anaesthetic into your wrist so you don’t feel anything while the surgery takes place. The whole procedure takes about 20 minutes after which you are free to go home.²

Peripheral neuropathy

Peripheral neuropathy occurs when the nerves located in your extremities such as your hands, arms, and feet are damaged. It has several causes:

• Type 2 diabetes is the most common one. This is the reason why people with diabetes often lose feeling in their lower legs and feet
• Excessive alcohol use (alcohol use disorder) can also damage your nerves
• Autoimmune disorders like lupus, Guillain-Barré syndrome, vasculitis, Sjögren's syndrome, rheumatoid arthritis, and chronic inflammatory demyelinating polyneuropathy (CIDP)

Circulatory causes

Poor blood circulation

Blood is pumped to all parts of the body by the heart and blood vessels. This blood carries essential nutrients as well as oxygen. Poor blood circulation happens when something disturbs this process and your body does not get enough blood. If the blood supply to your hands is blocked then it results in numb hands.⁷

Some of the conditions that may result in poor blood circulation and ultimately cause numb hands are:⁷

• Diabetes
• Smoking
• Raynaud’s disease
• Atherosclerosis
• High blood pressure
• Deep vein thrombosis (DVT)

Raynaud's disease

This is characterised by numbness in your feet and toes due to stress or cold temperatures. This numbness occurs because the arteries supplying blood to your feet and toes become narrowed, limiting their blood supply. 

This condition is more commonly found in people who reside in colder climates. Risk factors that may trigger Raynaud’s episode are the following:⁴

• Placing your hands in cold water
• Taking something out of a freezer
• Exposure to cold air
• Emotional stress

All of these factors cause the narrowing of arteries taking blood to your feet and toes, thus causing limited blood flow and numbness.

Raynaud’s disease can be primary or secondary. Primary Raynaud’s does not require treatment and you get better on your own, while Secondary Raynaud’s is more serious and can occur as a result of connective tissue or artery diseases. If Raynaud's is not getting better on its own, you should visit your healthcare provider so that they can assess the underlying cause of the disease and treat it accordingly.⁴ For instance, if your Raynaud’s episodes are often caused by cold temperatures, you should bundle up when exposed to a cold environment. If the cause is found to be a certain disease, your physician will prescribe you medication to treat that disease. Preventive measures for Raynaud’s include:⁴

• Stopping smoking
• Avoiding cold temperatures
• Managing and reducing stress

Orthopaedic causes

Arthritis

Arthritis, or more specifically rheumatoid arthritis, is one of the common causes of numbness in your hands and feet. Rheumatoid arthritis is an autoimmune disorder in which your body produces antibodies that attack your healthy joints, causing inflammation. These inflamed joints put pressure on the nerves surrounding them. This nerve compression results in tingly and numb hands and feet.

Rheumatoid arthritis can also lead to other conditions that worsen this numbness. Such conditions include carpal tunnel syndrome (CTS) and peripheral neuropathy.⁵

Herniated discs in the neck

A herniated disc in the neck (also called herniated cervical disc) is a condition in which the gel-like material inside one of your spinal discs (cushions between the bones in your spine) leaks out through a rupture in the surrounding wall, pressing onto the spinal nerves. This nerve compression causes numbness and tingling sensations in your hands and arms. Numbness in the hands is one of the lesser-known symptoms of a herniated cervical disc.⁶

Other causes

Hypothyroidism

Hypothyroidism occurs when your thyroid gland does not produce enough hormones. This condition can have many effects, including fluid build-up in your body. This fluid puts pressure on the nerves in your legs and arms. As a result, your hands and feet lose feeling and become tingly and numb.

Hypothyroidism can also cause carpal tunnel syndrome (CTS) and peripheral neuropathy, other causes of hand numbness (see the above sections).⁸

Medication side-effects

You can have numb hands as a side effect of certain medications. These medication include:⁹

• Chemotherapy medication (cisplatin, vincristine, paclitaxel)
• Antimicrobial medication (metronidazole, chloroquine, nitrofurantoin, isoniazid, dapsone)
• Cardiovascular medication (amiodarone, hydralazine)
• Seizure medication (phenytoin, carbamazepine, phenobarbital)
• Medication for alcohol abuse (disulfiram)
• Autoimmune disease medication (infliximab, etanercept, leflunomide)
• Gout medication (colchicine)
• HIV medication (didanosine, tenofovir, stavudine)

Other diseases

Other conditions that cause numbness in your hands are:

• Fibromyalgia
• Stroke
• Shingles
• Vasculitis
• Herpes infection
• Lyme disease
• Vitamin B12 deficiency 
• Multiple sclerosis
• Brachial plexus injury

FAQs

What are some common causes of hand numbness?

Numb hands can have multiple causes such as nerve compression, poor blood circulation, excessive use of your hands, injury, or diseases like carpal tunnel syndrome, and peripheral neuropathy.

Can poor posture also cause hand numbness?

Yes, poor posture can cause numbness in your hands. This is because poor posture in your neck and shoulders puts pressure on your nerves and causes nerve compression. This results in numb and tingly hands.

Do you feel numbness in your hands with diabetes?

Yes, you may feel numb hands and feet with diabetes. This is because diabetes can cause peripheral neuropathy which is defined as the damage to the nerves in your extremities (hands and feet). This nerve damage then causes your hands to become numb and tingly.

Does carpal tunnel syndrome cause numb hands?

Carpal tunnel syndrome is one of the most common causes of numbness in your hands. In this condition, the median nerve in your wrist gets compressed, causing your hands to become numb.

Are there any medications that cause hand numbness?

Certain medications have numbness in your hands as a side effect. These medications include certain chemotherapies, antimicrobials, cardiovascular and HIV treatments (a detailed list is given above).

Is it serious to have numbness in your hands during sleep?

If the numbness in your hands is temporary, it is likely caused by the compression of nerves when you sleep on your arm. This is not a cause for concern, however, if the numbness is persistent then medical attention is required.

Summary

Numbness in your hands, although not serious, should not be neglected if you have it for a long period, does not get better on its own or if it’s followed by other symptoms such as tingling, chest pain, slurred speech, weakness etc. This indicates that you have some serious disease and you should visit your healthcare provider for a checkup and potential treatment. Your physician will first check the cause of this numbness and prescribe the treatment accordingly. Some of the common causes of numb hands are carpal tunnel syndrome, peripheral neuropathy, fibromyalgia, rheumatoid arthritis, Raynaud’s disease, hypothyroidism, and herniated cervical discs. Hand numbness can be prevented by removing the underlying cause and avoiding activities that enhance it.