My left hand has been tingling all day

Causes of numbness and tingling can range from sitting in one position for too long to insect bites to multiple sclerosis. Discover even more causes, and learn when to get medical attention.

Numbness and tingling are unusual prickling sensations that can happen in any part of your body. People generally notice these sensations in their:

• hands
• feet
• arms
• legs

The medical term for numbness and tingling is “paresthesia.” Many things can cause numbness and tingling, including sitting with your legs crossed or falling asleep on your arm.

Sometimes numbness and tingling persist, and there’s no obvious cause for the sensations. They could be symptoms of a condition, such as multiple sclerosis, or an injury.

Treatment for numbness and tingling will depend on your diagnosis.

Things that we do every day can sometimes cause numbness, including:

• standing or sitting in one position for a long time
• sitting cross-legged
• falling asleep on your arm

The examples above place pressure on your nerves. Once you move, the numbness will get better.

Possible causes of numbness and tingling are numerous, and they include:

• an insect or animal bite
• mercury and other toxins found in seafood
• atypically low levels of vitamin B12, potassium, calcium, or sodium
• radiation therapy
• medications, especially chemotherapy

Sometimes, a specific injury can produce numbness and tingling, such as an injured nerve in your neck or a herniated disc in your spine. Other possible causes are below.

Nerve pressure

Placing pressure on a nerve is another common cause of numbness and tingling.

The following can place pressure on one or more nerves:

• enlarged blood vessels
• ligaments, tendons, and surrounding soft tissues
• scar tissue
• a tumor
• infection
• inflammation or swelling of the spinal cord or brain

Skin damage

Damage to the skin via a rash, inflammation, or an injury is another reason for numbness and tingling.

Conditions that can cause this type of skin damage include frostbite and shingles.

Medical conditions

Some conditions produce numbness and tingling as symptoms. Examples include:

• diabetes
• migraine
• Raynaud’s phenomenon, which causes reduced blood flow to the extremities, such as the fingers and toes
• multiple sclerosis
• neuropathy or nerve damage, such as carpal tunnel syndrome
• seizure disorders
• stroke
• ministroke, also known as a transient ischemic attack
• atherosclerosis, or hardening of the arteries
• underactive thyroid

Everyone can experience numbness and tingling on occasion. You probably felt it in the past when you stood up after sitting in one position for a long time. It usually resolves within minutes.

However, consult a doctor if you have:

• continued numbness and tingling, and there’s no obvious cause
• dizziness
• muscle spasms
• a rash

Also, tell the doctor if the symptoms in your legs worsen when you walk or if you urinate more frequently than usual.

Expect the doctor to request a complete medical history. Be sure to report all symptoms, even if they don’t seem related, as well as any diagnosed conditions. Note if you had any recent:

• injuries
• infections
• vaccinations

The doctor will also need to know about any prescription or over-the-counter medications and supplements you take.

Depending on the findings of your physical exam, the doctor may order additional tests. These may include:

• a complete blood count
• electrolyte level tests
• vitamin level tests
• thyroid function tests
• toxicology screens
• nerve conduction studies

Imaging tests of the affected area can help the doctor reach a diagnosis. The doctor may also perform one or more of the following imaging tests:

• X-ray
• CT scan
• MRI
• ultrasound
• angiogram of your arteries

Because of the varied causes of numbness and tingling, your treatment will depend on the reason for your symptoms.

Treatment will focus on resolving any underlying medical conditions and will likely consist of medications.

Other treatments may include:

• topical remedies, such as creams
• supplements
• physical therapy
• exercise
• wearing a splint or brace
• lifestyle changes, such as modifying your diet

If you experience numbness and tingling, you may also have reduced feeling in the affected areas. Because of this, you can be less likely to feel temperature changes or pain. This means that you might touch something without realizing it’s hot enough to burn your skin.

Alternately, a sharp object might cut your skin without you even noticing. Make sure you take precautions to protect yourself from burns and other accidental injuries.