causes-of-charley- horses

Charley horses, a painful muscle spasm in the leg or foot, can happen to people of all ages and lifestyles. Worse yet, they can strike at any time of the day or night, though it’s common to have muscle cramps while sleeping. 

Although they appear to happen randomly, some habits and conditions have been linked to charley horses, and there are steps you can take to prevent them. 

What Is a Charley Horse? 

A charley horse is another name for a muscle spasm, which is when a muscle contracts and will not relax. Muscle spasms can happen to any muscle in the body, but they are most common in the leg and foot. During a muscle spasm, the muscle becomes hard and tight and may be tender to the touch. After the spasm subsides, the muscle may be sore for hours or even days. 

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What Causes Charley Horses? 

While there is no definite cause for charley horses, several factors make their occurrence more likely, including: 

  • Overusing the muscle: This is the most common cause. Overuse of the muscle can place an extra strain on it, causing a cramp or spasm. 
  • Dehydration: If your body is losing more water than it’s taking in, such as during exercise, it can cause your body not to function properly. 
  • Exercising in very hot or cold temperatures: Exercising in heat can more easily cause dehydration, while cold weather may affect your body’s ability to warm up properly. 
  • Stress: Your muscles can become tense under stress, leading to spasms. 
  • Poor blood flow/circulation: If not enough blood is getting to your muscles, this can cause cramps. 
  • Not getting enough vitamins/minerals: A lack of electrolytes (sodium, potassium, magnesium, and calcium) can cause muscles to spasm. 
  • Standing or sitting too long without moving: Periods of inactivity can reduce blood flow to the muscles. This also can happen while sleeping. 
  • Malfunctioning nerves: Problems such as a spinal cord injury or a pinched nerve in the neck or back can cause signal disruption to the muscles. 
  • Certain medications: Drugs that can cause cramps include diuretics (for high blood pressure, heart failure, and kidney disease), nicotinic acid and statins (for high cholesterol), raloxifene (osteoporosis prevention), and nifedipine (for angina and Raynaud’s phenomenon). 
  • Pregnancy: The extra weight of pregnancy can put more strain on leg muscles. 
  • Liver disease: Toxins can build up in your system, which can cause muscle spasms. 
  • Infections: Bacterial infections like tetanus can cause muscle cramps. 

Who Is At-Risk? 

Groups at risk for muscle cramps and spasms include: 

  • Athletes. 
  • Overweight/obese individuals. 
  • Older adults. 
  • Pregnant women. 
  • People with medical conditions like thyroid and nerve disorders. 

Charley Horse Treatments 

Most of the time, muscle spasms resolve on their own. To help ease the pain when they happen, you can try one of the following: 

  • Apply heat during the cramp and ice after it ends. 
  • Gently stretch the muscle: If you’re suffering from a calf cramp, you can get relief by laying down with your leg straight, lifting your foot, and bending your ankle so your toes point toward your shin. This causes the injured muscles to move in the opposite direction of the contracted muscles, loosening the tightness. 
  • Massage the muscle.
  • Drink fluids.
  • Take anti-inflammatory medicines if the pain remains after heat and ice. 

The best treatment for charley horses is prevention. You can take steps to prevent them by: 

  • Drinking plenty of water. 
  • Stretching before and after exercise or before bed if you experience cramps at night.
  • Eating foods high in magnesium, potassium, and calcium. 
  • Wearing comfortable, supportive shoes. 
  • Adjusting your exercises. 

The American Academy of Orthopaedic Surgeons recommends the following stretches to prevent charley horses: 

  • Calf stretch: Place both hands on a wall and lean forward with one leg in front of the other. Straighten your back leg and press your heel into the floor. Your front knee will be bent. Hold for 15 to 30 seconds and repeat for the other leg. 
  • Hamstring stretch: While on the ground, sit tall and point both legs straight in front of you. Put your palms flat on the ground and slide them toward your ankle. Stop when you feel the stretch. 
  • Quadriceps stretch: While holding on to a wall or the back of a chair for balance and support, grasp your foot and bend your leg backward, bringing your heel toward your buttocks. Pull your heel closer to your body and hold position for 30 seconds. Repeat with the other leg. 

Why Do Charley Horses Hurt So Badly? 

 The pain you feel from a charley horse can be severe because your muscle is fatigued from the continual contraction. Since you are unable to control and relax the muscle, it can continue to feel painful even after the muscle contraction has subsided.  

When to See a Doctor 

In some cases, repeated charley horses can be the result of nerve issues, which can be diagnosed with an MRI scan. 

If you experience muscle spasms frequently, they may be a symptom of an underlying health condition such as: 

Consult your doctor if your cramps: 

  • Are frequent. 
  • Are severe. 
  • Don’t go away with home treatment. 
  • Last a long time. 
  • Cause you to experience swelling, redness, or warmth in the affected area.
  • Cause muscle weakness. 
  • Spread to another part of the body. 

“If you are experiencing charley horses after starting new medication, talk to your doctor,” says Shane Eikenberry, MD, a primary care physician at Greater Pittsburgh Medical Associates-UPMC. “Sometimes charley horses can be a side effect of certain medications that change your electrolyte balance. Most commonly these are diuretics (“water pills”), blood pressure medications, and heart medications.” 

Charley horses, a painful muscle spasm in the leg or foot, can happen to people of all ages and lifestyles. Worse yet, they can strike at any time of the day or night, though it’s common to have muscle cramps while sleeping.

Although they appear to happen randomly, some habits and conditions have been linked to charley horses, and there are steps you can take to prevent them.

Editor's Note: This article was originally published on , and was last reviewed on .

U.S. National Library of Medicine. Muscle Cramps. Kevin C. Miller, PhD, ATC, CSCS, Marcus S. Stone, PhD, ATC, [...], and Jeffrey E. Edwards, PhD. Exercise-Associated Muscle Cramps. Sports Health. Take that, muscle cramps!. Harvard Health Publishing. American Academy of Orthopaedic Surgeons. Muscle Cramps. NHS Inform. Leg Cramps. North American Spine Society. Muscle Spasms. U.S. National Library of Medicine. Charley Horse. AARP. Charley Horse Pain Relief.

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