Last reviewed: 25 Jun 2021
Last updated: 24 Jul 2018



History and exam

Key diagnostic factors

  • hx of concurrent hemodialysis (organic cause)
  • hx of cirrhosis (organic cause)
  • pregnancy (idiopathic cramp)
  • hx of strenuous exercise (idiopathic cramp)
  • hx of medication use (idiopathic cramp)
  • nocturnal onset (idiopathic cramp)
  • gastrocnemius muscle involvement, with or without foot involvement (idiopathic cramp)
  • duration <10 minutes (idiopathic cramp)
  • predominantly unilateral (idiopathic cramp)
  • precipitation by both trivial movements and by forceful contractions (idiopathic cramp)
  • visible or palpable muscular knotting
  • good response to passive/active stretching (idiopathic cramp)
  • normal neurologic exam (idiopathic cramp)
  • normal general physical exam (idiopathic cramp)
  • other local muscle involvement (neuromuscular disease cramp)
  • widespread muscle cramps (lower motor neuron disease)
  • duration >10 minutes (organic cause)
  • abnormal neurologic exam (organic cause)
  • abnormal musculoskeletal exam (organic cause)

Other diagnostic factors

  • signs of a chronic medical condition (organic cause)

Risk factors

  • pregnancy
  • strenuous exercise
  • hemodialysis
  • cirrhosis
  • imatinib
  • beta-blockers with intrinsic sympathomimetic activity
  • statins
  • age >60 years
  • female gender
  • FHx of cramp
  • other prescribed drugs
  • creatine supplementation
  • hypoglycemia in diabetes mellitus
  • chronic diseases
  • home parenteral nutrition

Diagnostic investigations

Investigations to consider

  • serum hCG
  • fasting serum metabolic panel
  • TSH
  • HbA1c
  • serum LFTs
  • PT and INR
  • serum myoglobin and urinalysis
  • serum CK-MM
  • serum alpha-tocopherol (vitamin E)
  • serum zinc
  • EMG
  • nerve conduction studies
  • serum aldolase
  • muscle biopsy
  • genetic studies

Treatment algorithm



Michael Rubin, MD, FRCP(C)

Professor of Clinical Neurology

Weill Cornell Medical College

Attending Neurologist

Director, Neuromuscular Service and EMG Laboratory

New York Presbyterian Hospital

New York



MR is an assistant editor for Neurology Alert and a contributor to Merck Manuals.


Dr Michael Rubin would like to gratefully acknowledge Dr Justin Mhoon and Dr David R.P. Guay, previous contributors to this monograph. JM declares that he has no competing interests. DRPG is an author of a reference cited in this monograph.

Peer reviewers

Timothy M. Miller, MD, PhD

Assistant Professor of Neurology

Department of Neurology

Washington University School of Medicine

St. Louis



TMM is an author of a reference cited in this monograph.

Sami Khella, MD


Department of Neurology

Penn Presbyterian Medical Center

University of Pennsylvania Health System




SK declares that he has no competing interests.

Felicity Goodyear-Smith, MB CHB, DipObs, MGP, FRNZCGP, MFFLM, RCP

Professor and Goodfellow Postgraduate Chair

Department of General Practice & Primary Health Care

University of Auckland


New Zealand


FG-S declares that she has no competing interests.

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