What causes muscle spasms?

Skeletal muscle spasms and cramps often occur when a muscle has been overused or overstretched. Muscle cramps can also be caused or worsened by dehydration and not getting enough fluids.

Muscle spasms and cramps can also be due to neuromuscular disorders and various diseases and conditions that affect the whole body, including diabetes, anemia, kidney failure, and thyroid disorders. In some cases, muscle spasms may be a symptom of a serious or life-threatening condition, such as a heart attack, tetanus (lockjaw), cancer, or severe dehydration.

Common causes of muscle spasms

Several common conditions that can cause muscle spasms and cramps include:

  • Dehydration
  • Holding your body or muscle in one position for a long time
  • Muscle strain
  • Overuse or repetitive motion

Neuromuscular diseases, disorders and conditions that can cause muscle spasms

A number of conditions that affect the muscles or nerves can produce muscle spasms. These include:

  • Amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s disease; a severe neuromuscular disease that causes muscle weakness and disability)
  • Brain or spinal cord injury
  • Multiple sclerosis (disease that affects the brain and spinal cord)
  • Muscular dystrophy (inherited disorder that causes a progressive loss of muscle tissue and muscle weakness)
  • Myositis (muscle inflammation)
  • Parkinson’s disease (brain disorder that impairs movement and coordination)
  • Peripheral neuropathy (possible pelvic mass)
  • Pinched nerve (nerve compression)
  • Polio
  • Stroke

Causes of smooth muscle spasms

Smooth muscles are muscles located in the walls of hollow organs in your body, such as your stomach, bladder, and blood vessels. Causes or types of smooth muscle spasms include:

  • Raynaud’s disease and blood vessel spasms
  • Bladder infection and spasms of the bladder wall
  • Gallstones and colic
  • Esophageal spasms
  • Food poisoning and intestinal spasms
  • Kidney stone
  • Labor and childbirth
  • Menstruation
  • Prinzmetal’s angina (due to spasms in the arteries that supply the heart). Coronary artery spasms can lead to life-threatening cardiac arrhythmias (abnormal heart rhythms) and heart attack.

Other possible causes of muscle spasms

Muscle spasms and cramps can be caused by a variety of other diseases, disorders and conditions including:

  • Alcohol abuse and alcoholism
  • Heart attack
  • Hypothyroidism
  • Inherited metabolic disorders such as enzyme deficiencies
  • Kidney failure
  • Peripheral artery disease (PAD, also called peripheral vascular disease, or PVD, which is a narrowing of the arteries due to a buildup of fat and cholesterol on the artery walls, which limits blood flow to the extremities)
  • Potassium or calcium (electrolyte) imbalance
  • Pregnancy
  • Systemic lupus erythematosus (disorder in which the body attacks its own healthy cells and tissues)
  • Vitamin B12 or D deficiency

Medications and substances that can cause muscle spasms

Medications that can cause muscle spasms and cramps include:

  • ACE inhibitors for lowering blood pressure
  • Cocaine
  • Corticosteroids
  • Diuretics (“water pills”)
  • Estrogens
  • Statins for lowering cholesterol
  • Toxins such as nerve gas or insecticides
  • Zidovudine

Questions for diagnosing the cause of muscle spasms

To help diagnose the underlying cause of muscle spasms, your licensed health care provider will ask you several questions related to your symptoms. Giving complete answers to these questions will help your provider diagnose the cause of your muscle spasms:

  • Are you receiving hemodialysis?
  • What is your routine sleep posture?
  • Do you feel spasms in one particular muscle or in several different areas?
  • What body parts are affected?
  • How long have you had spasms? How long do the spasms last?
  • Are you experiencing any other symptoms at the same time, such as a sore throat or fever?
  • What makes your symptoms better or worse?
  • What other medications, if any, are you currently taking?

What are the potential complications of muscle spasms?

Complications associated with muscle spasms depend on the underlying disease, disorder or condition. For example, muscle spasms resulting from a degenerative condition, such as multiple sclerosis can lead to inactivity and its associated complications. Fortunately, most cases of muscle spasms can often be alleviated or minimized by physical therapy, basic self-help measures, and following the treatment plan outlined by your doctor.

With time, repetitive muscle spasms and their underlying cause can lead to complications including:

  • Chronic muscle spasms
  • Muscle contracture
  • Muscle pain
  • Permanent nerve damage (due to a pinched nerve) including paralysis
  • Physiological and psychological response to chronic muscle spasms
  • Poor quality of life


  1. Muscles. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/tutorials/muscles/htm/index.htm.
  2. Muscle Cramps. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/003193.htm
  3. Esophageal Spasm. PubMed Health, a service of the NLM from the NIH. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001334.
  4. Maquirriain J, Merello M. The athlete with muscular cramps: clinical approach. J Am Acad Orthop Surg 2007; 15:425.

What are muscle spasms?

A muscle spasm is a painful, involuntary movement or contraction of a muscle. A muscle spasm is also known as a muscle cramp. Muscle spasms and cramps are not the same as muscle twitching, which refers to very fine involuntary movements (fasciculations) of a small segment of muscle.... Read more about muscle spasmsintroduction


What other symptoms might occur with muscle spasms?

Muscle spasms may occur with other symptoms, which vary depending on the underlying disease, disorder or condition. For example, severe skeletal muscle spasms may be accompanied by bruising and swelling of the area. Muscle spasms that are caused by a disorder affecting your whole body, such as hypothyroidism, may be associ... Read more about muscle spasmssymptoms

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

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