Charley horse is another name for a muscle spasm or muscle cramp. It’s marked by involuntary, uncomfortable, and sometimes painful muscle contractions that may last a few minutes.

A charley horse is a muscle cramp that may cause involuntary spasms in:

  • a single muscle, such as the biceps
  • a group of muscles, such as the quadriceps
  • muscle fibers

They may last up to a few minutes and will typically go away on their own. It’s common to feel a muscle knot in the affected area that may feel tight or tender. Muscle spasms are most common in the legs.

In some cases, severe charley horses may result in muscle soreness that lasts anywhere from a few hours to a day.

Keep reading to learn more about the causes, risk factors, and treatment for a charley horse.

According to the American Academy of Orthopaedic Surgeons, the exact causes of a charley horse and muscle cramping aren’t fully understood.

However, researchers have identified several factors that may contribute to a charley horse, including:

  • dehydration
  • overuse of a specific muscle, such as during exercise
  • electrolyte imbalances, such as calcium, potassium, and sodium
  • sitting or lying down in the same position for a long period
  • inadequate blood flow to the muscle
  • exercising in excessive heat or cold
  • stress, most often in the neck muscles
  • not stretching before exercise
  • compressed nerves, such as in the spine
  • taking certain medications, such as diuretics, beta-blockers, and statins

Risk factors

Several risk factors may increase your risk of experiencing charley horses.

For instance, it’s estimated that 37% of people ages 60 years and older in the United States experience leg cramps at night (nocturnal leg syndrome), most commonly in the calf muscle.

Similarly, up to 1 in 2 people who are pregnant experience leg cramps, mostly during the third trimester.

Athletes may experience charley horses more often because of muscle fatigue or overuse. Having overweight or being sick may also increase your risk.

Medical conditions

Several medical conditions may increase your risk of experiencing charley horse, including:

Many people experience charley horses during sleeping hours and are awakened because of them.

The occasional charley horse doesn’t require an official medical diagnosis.

However, consider speaking with a healthcare professional if you experience frequent, recurrent muscle spasms, such as if a charley horse occurs more than once a week without an obvious reason.

A doctor will first ask about your medical history and perform a physical examination. This may involve pressing the affected area to check for a point of tension, like a muscle knot.

They may also order other tests to help determine the underlying cause, such as:

  • electromyography to help assess the health of the nerve cells that control your muscles
  • MRI scans to help determine whether you have nerve compression
  • blood tests to rule out electrolyte imbalances

When to worry about charley horses

Consider speaking with a healthcare professional if:

  • you experience frequent muscle cramps and spasms
  • they last longer than 10 minutes
  • they affect your sleep
  • you experience other symptoms, such as numbness and tingling

Treatment for a charley horse will depend on the severity, frequency, and underlying cause of the muscle spasms. In most cases, charley horses will heal on their own without any medical treatment.

Stretching the affected area or deeply massaging it is most often the best way to stop the muscle spasm.

During a charley horse, stretch the affected area and hold it until the muscle spasms stop. You can also try using both of your thumbs to apply pressure to the site of the cramp until the pain goes away.

Other home remedies that may help include:

If you experience recurring muscle spasms and these home remedies don’t help, speak with a doctor. They may recommend doing physical therapy or taking over-the-counter or prescription medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs) or antispasmodic medication.

Once you identify the cause of the occasional charley horse, symptoms are generally easy to prevent. Take these steps to help avoid future muscle spasms:

  • Stretch before and after exercise.
  • Avoid exercising the same muscles on consecutive days.
  • Don’t exercise in severe weather.
  • Drink water throughout the day.
  • Drink beverages that contain electrolytes, such as low sugar sport beverages.
  • Stretch before going to bed.

Charley horses are common and may occur in any muscle at any time. They’re usually treatable and can sometimes be prevented.

Any pain caused by a spasm won’t typically last more than a day. However, if you experience charley horses frequently, talk with a doctor about treatments.