What causes leg cramps?

Leg cramps can be due to muscle overuse, injury, or fatigue and may be related to decreased blood supply or irritation of the nerves leading to a muscle. Most of the time the genuine cause for a leg cramp is not identified. Most leg cramps resolve spontaneously without any treatment whatsoever. Dehydration and electrolyte depletion can increase the likelihood of developing muscle cramps. Medications may also contribute to the development of leg cramps. Dehydration can also occur with excessive sweating, which may occur when exercising in hot weather.

Causes of leg cramps

Leg cramps may be caused by diseases, disorders or conditions including:

  • Dehydration
  • Low blood calcium, magnesium, potassium, or sodium
  • Muscle fatigue, injury, or overuse
  • Peripheral artery disease (PAD, also called peripheral vascular disease, or PVD, which is a narrowing or blockage of arteries due to a buildup of fat and cholesterol on the artery walls, which limits blood flow to the extremities)
  • Pregnancy
  • Renal hemodialysis
  • Sciatica (pain or weakness in the leg due to damage to the sciatic nerve from the spine to the back of the leg)
  • Side effects of medications, such as diuretics and statins
  • Spinal cord stenosis

Serious or life-threatening causes of leg cramps

In some cases, leg cramps may be a symptom of a serious or life-threatening condition that should be immediately evaluated in an emergency setting. These include:

  • Peripheral neuropathy (possible pelvic mass)
  • Severe dehydration
  • Significant electrolyte abnormalities

Questions for diagnosing the cause of leg cramps

To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your leg cramps including:

  • Are you receiving hemodialysis?
  • How long have you had leg cramps?
  • What part of the leg do they affect?
  • What is your usual sleep posture?
  • How often do they occur and how long do they last?
  • Does anything seem to bring them on?
  • Does anything make them better?
  • Do you have any other symptoms?
  • What medications are you taking?

What are the potential complications of leg cramps?

Because leg cramps can be due to serious diseases, failure to seek treatment for leg cramps that are not relieved with self-care measures can result in serious complications and permanent damage. Once the underlying cause is diagnosed, it is important for you to follow the treatment plan that you and your health care professional design specifically for you to reduce the risk of potential complications including:

  • Loss of mobility
  • Nonrestorative sleep
  • Overuse injuries
  • Progressive symptoms
  • Skin changes


  1. Leg pain. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/003182.htm.
  2. Muscle cramps. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/musclecramps.html.
  3. Maquirriain J, Merello M. The athlete with muscular cramps: clinical approach. J Am Acad Orthop Surg 2007; 15:425.

What are leg cramps?

Leg cramps, sometimes called charley horses, are sudden and uncontrollable muscle contractions or spasms. They can occur with exercise or while sleeping and usually resolve just as quickly as they came. The pain from muscle cramps can be intense, but can often be relieved with gentle stretching and massage.... Read more about leg crampsintroduction


What other symptoms might occur with leg cramps?

Leg cramps may accompany other symptoms that vary depending on the underlying disease, disorder or condition. Conditions that frequently affect your muscles may also involve other body systems.

Other symptoms that may occur along with leg cramps

Leg cramps may accompany other symptoms including:

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Sep 6, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Bones, Joints and Muscles

What's Causing Your Symptoms?