A muscle spasm — also known as a charley horse, muscle cramp or twitch — is a sudden, involuntary movement in one or more muscles. Common causes include stress, exercise, or dehydration, but nerve disorders and thyroid problems may increase the risk.

These movements can happen in any muscle of the body, but often affect the calf muscle. They are very common and mostly not a cause for concern.

Muscle spasms are very common. They can happen in any part of the body, but they tend to affect the:

  • feet
  • hands
  • arms
  • thighs
  • abdomen
  • intercostal muscles, which are around the rib cage

Muscle pain, fatigue, and overuse are the most common causes of muscle spasms. Other causes include stress or anxiety, which can lead to muscle twitches in the face. Trapped nerves can result in spasms in the back.

Athletes who either do not warm up before they exercise or exercise in very hot conditions may also experience muscle spasms. Charley horse, for example, is a term that people often use to describe spasms in runners’ calf muscles. Drinking insufficient water before exercise can also cause muscle spasms.

Some people are more vulnerable than others to muscle spasms. Those who are most at risk are:

  • older adults
  • athletes
  • people with overweight or obesity
  • pregnant women

People who have certain health conditions, such as nerve disorders or thyroid-related problems, also tend to experience a higher-than-average frequency of muscle spasms.

Muscle spasms are not usually anything to worry about, but in some cases, they can be a sign of an underlying neurological health condition. Neurological health conditions affect the brain, which is responsible for making the muscles move.

Not all muscle spasms are painful, but some can cause pain. It can feel as though the muscle is jumping or moving on its own, with this feeling typically lasting just a few seconds. Some people might even be able to see the muscle twitching.

Sometimes, it can feel as though the whole muscle has cramped up and cannot move. This effect most commonly happens in the legs, and it can be quite painful. The muscle may feel hard to the touch. While the cramping sensation tends to pass within several minutes or so, the muscle may continue to hurt for some time afterward.

If a muscle spasm is part of a neurological health condition, the person will usually experience other symptoms. These might include:

  • pain in the back, neck, or head
  • weakness in the muscles
  • skin numbness
  • a pins-and-needles sensation
  • a tremor
  • paralysis
  • poor coordination
  • slow movements
  • double vision
  • sleep problems

Muscle spasms usually resolve on their own. It might take a few seconds or even several minutes for them to stop, but they do not often need treatment. Drinking plenty of water can help ease dehydration-related muscle cramps.

If someone has a painful cramp, they can try a few methods to help ease the symptoms. The American Osteopathic Association recommend:

  • stopping any activity that led to the cramp — running, for example
  • massaging the cramping muscle gently
  • stretching the cramping muscle gently
  • using a heating pad to relax tight muscles
  • applying an ice pack to soothe sore muscles

If the pain is in the calf muscle, the person can try putting their weight on the affected leg and bending their knee slightly. Doing this will stretch the muscle.

If cramping affects the quadriceps — the muscles at the front of the thigh — the person can try holding the foot of the affected leg behind them and gently pulling it up toward their buttocks, keeping the knees together.

In cases where an underlying neurological condition is causing the muscle spasms, doctors may recommend an antispasmodic medicine.

Drinking plenty of water and stretching the muscles before any exercise or repetitive movements can help prevent muscle spasms.

Some people experience muscle cramps in the legs during the night. Stretching the limbs before bed can help prevent this from occurring.

Muscle spasms, twitches, and cramps are not usually a cause for concern. They are perfectly normal, particularly in athletes and other people who exercise regularly.

In some cases, however, they can indicate an underlying health condition, such as multiple sclerosis, thyroid disease, or cirrhosis of the liver. They may also suggest problems with:

  • nutrition
  • circulation
  • metabolism
  • nerves
  • hormones

Anyone who regularly experiences severe or painful muscle spasms should speak to a doctor.

Muscle spasms are very common, and people do not usually need to worry about them. Overexercising, dehydration, and stress are the most common causes.

The spasms happen when the muscle suddenly moves involuntarily. Muscle spasms may feel like a slight twitch or a painful cramp, and they can occur in the muscles in any part of the body.

Muscle spasms can last just a few seconds or up to several minutes, but they tend to go away on their own without any treatment. Gently stretching or massaging the affected area or using a heat or ice pack may help.

Sometimes, muscle spasms can be a sign of an underlying health condition. Anyone who suffers from frequent or severe muscle spasms should speak to a doctor.

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