Thumb twitching, also called a tremor, happens when thumb muscles contract involuntarily, causing your thumb to twitch. Twitching can result from activity in nerves connected to your thumb muscles, stimulating them and causing the twitching.

Thumb twitching is usually temporary and rarely caused by a serious condition.

If thumb twitching disrupts your everyday activities, you can see a doctor to diagnose the cause.

Some causes of thumb twitching result from your lifestyle, such as your exercise routine or diet. Others are caused by conditions that affect your nervous system.

Autoimmune disorders

Some conditions can cause your nerves to stimulate your muscles involuntarily. One rare condition with this symptom is Isaacs’ syndrome.

Cramp-fasciculation syndrome (CFS)

This rare muscle condition, also known as benign fasciculation syndrome, causes your muscles to twitch and cramp because of overactive nerves.

Drug overdose

Taking stimulants can make your muscles twitch. A drug overdose includes substances that are perfectly safe in moderation, such as caffeine or over-the-counter energy drinks, but also includes dangerous stimulants like amphetamines or cocaine.

Lack of sleep

If you don’t get enough sleep, neurotransmitters can build up in your brain nerves, causing thumb twitching.

Drug side effects

Certain medications can cause thumb twitching. Diuretics for urinary issues, corticosteroids, and estrogen supplements may all have this side effect.

Exercise

Your muscles are prone to twitching after exercise, especially high-intensity exercises like running or lifting weights.

This happens when your body doesn’t have enough oxygen to turn a metabolic substance called lactate into energy. Extra lactate is stored in the muscles, and when it’s needed, it can cause muscle contractions.

Nutritional deficiency

Not getting enough of certain vitamins and nutrients, such as B-12 or magnesium, can cause thumb twitching.

Stress

Stress is one of the most common causes of thumb twitching. The muscle tension that results from stress can trigger muscle contractions all over your body.

Medical conditions

Conditions that affect your body’s ability to metabolize (produce energy) can affect your muscles.

These metabolism disorders can include having low potassium absorption, kidney disease, and uremia (having urea, a component of urine, at high levels in your blood).

Benign twitches

Your thumb muscles can twitch at any time without warning. Anxiety and stress may trigger benign twitching in your thumbs as well as your calves or eyelids. These twitches usually don’t last long and may appear irregularly.

Electronics use

Using your thumbs for a long period of time on your mobile phone or other can cause weakness, fatigue, or stress in your thumbs. The constant motion of typing or pressing buttons can make your thumbs twitch if you don’t regularly rest them.

Central nervous system causes

Thumb twitching can also be a symptom of a central nervous system condition:

  • Amyotrophic lateral sclerosis (ALS). ALS is a type of nervous system condition that happens when motor neurons, which help transmit nerve signals from your brain to your muscles, weaken and die over time.
  • Parkinson’s disease. Hand tremors are one of the first symptoms of Parkinson’s, a condition in which neurons in your brain are lost over time.
  • Nerve damage (neuropathy). Neuropathy happens when nerves become damaged by injury, repetitive motion, and conditions like diabetes and kidney disorders that cause harmful toxins to build up in your body. Peripheral neuropathy is the most common, affecting more than 20 million people in the United States alone.
  • Spinal muscular atrophy. Spinal muscular atrophy is a genetic condition that causes you to lose motor neurons over time.
  • Muscle weakness (myopathy). Myopathy is a condition that happens when your muscle fibers don’t function properly. There are three types of myopathy, and the most common, which includes muscle weakness, is myositis.

Symptoms of nervous system conditions

Common symptoms include:

  • headaches
  • tingling in your hands, feet, and other extremities
  • changes in sensations, such as numbness
  • trouble walking
  • losing muscle mass
  • weakness
  • double vision or vision loss
  • memory loss
  • muscle stiffness
  • slurring of speech

You don’t need treatment for benign thumb twitching. It will stop on its own, though it can last up to a few days.

But if your thumb twitching is caused by an underlying condition, you may need to seek treatment. Here are some possible treatments:

See your doctor if twitching:

  • doesn’t go away after a couple of weeks
  • interferes with daily activities, such as writing or typing

Symptoms of a central nervous system disorder should also prompt you to visit a doctor.

Diagnostic tests to identify the cause, such as nutritional deficiency, spinal injury, brain tumor, or other serious condition, include:

You can help prevent some causes of thumb twitching:

  • Avoid your triggers. If caffeine, sugar, or alcohol cause twitching, limit how much you consume or avoid them altogether.
  • Manage your stress. Meditating and breathing exercises can both help reduce twitching caused by stress.
  • Limit electronics usage.
  • Get a good night’s rest. Sleep seven to eight hours a night consistently.
  • Eat a healthy diet. Drink at least 64 ounces of water a day and make sure you’re getting plenty of vitamins B-6, B-12, C, and D.

There’s usually no need to feel concerned about a thumb twitch — it’ll most likely go away on its own.

If thumb twitching is constant or you notice other unusual symptoms, see a doctor to diagnose underlying conditions causing your muscle contractions.