Idiopathic leg cramps
BioMG follows French guidelines. Adapt it to the guidelines and the tests available where you practise.
Idiopathic leg cramps
Laboratory tests, only if the context justifies them
- hCGif needednon-French guidelinePossible pregnancy, which is associated with nocturnal leg cramps [1].
- FBCif needednon-French guidelineAnaemia suspected for another clinical reason: American Family Physician finds no demonstrated association between cramps and anaemia, so the FBC is not a test for the work-up of the cramps themselves [1].
- Serum creatinine with eGFRif neededEnd-stage renal disease or haemodialysis (associated with cramps) [1,2]; no demonstrated association with lesser renal impairment [1].
- Serum sodium, serum potassiumif needednon-French guidelineDehydration, diarrhoea, vomiting or diuretics (authors' opinion); American Family Physician found no association of cramps with hypovolaemia or with disturbances of potassium, sodium and magnesium, hence the optional nature [1].
- Serum magnesiumif neededDiffuse or frequent cramps (calcium and magnesium) or hyperreflexia (calcium) (authors' opinion).
- Serum calciumif neededDiffuse or frequent cramps (calcium and magnesium) or hyperreflexia (calcium) (authors' opinion).
- Serum albuminif neededTo interpret serum calcium if it is requested and serum albumin may be abnormal (authors' opinion).
- Plasma glucoseif needednon-French guidelineDiabetes or hypoglycaemia in a treated diabetic patient (authors' opinion); no demonstrated association between cramps and blood glucose outside this context [1].
- Creatine kinase (CK)if needednon-French guidelineSuspected myopathy: muscle weakness, deep pain or poor exercise tolerance, or statin use [1].
- TSHif needednon-French guidelineSuspected thyroid dysfunction (authors' opinion); no demonstrated association between cramps and thyroid function in the absence of other signs [1].
- ASTif neededKnown or suspected cirrhosis, alcoholism, liver disease; cramps of the thighs and fingers [1,2].
- ALTif neededKnown or suspected cirrhosis, alcoholism, liver disease; cramps of the thighs and fingers [1,2].
- ALPif neededKnown or suspected cirrhosis, alcoholism, liver disease; cramps of the thighs and fingers [1,2].
- GGTif neededKnown or suspected cirrhosis, alcoholism, liver disease; cramps of the thighs and fingers [1,2].
- Vitamin B12if neededAssociated peripheral neuropathy [1,2].
Do not order
Leg cramps: targeted tests according to the context
Laboratory tests, only if the context justifies them
- hCGif neededPossible pregnancy.
- Serum creatinine with eGFRif neededEnd-stage renal disease or haemodialysis.
- Serum sodium, serum potassiumif neededContext of dehydration, diarrhoea, vomiting or diuretic use.
- Serum magnesiumif neededDiffuse or frequent cramps (calcium and magnesium) or hyperreflexia (calcium).
- Serum calciumif neededDiffuse or frequent cramps (calcium and magnesium) or hyperreflexia (calcium).
- Plasma glucoseif neededDiabetes or hypoglycaemia in a treated diabetic patient.
- Creatine kinase (CK)if needednon-French guidelineSuspected myopathy: muscle weakness, deep pain or poor exercise tolerance, or statin use [1].
- TSHif neededSuspected thyroid dysfunction.
- ASTif neededCramps of the thighs and fingers, context of alcoholism, liver disease or advanced cirrhosis.
- ALTif neededCramps of the thighs and fingers, context of alcoholism, liver disease or advanced cirrhosis.
- ALPif neededCramps of the thighs and fingers, context of alcoholism, liver disease or advanced cirrhosis.
- GGTif neededCramps of the thighs and fingers, context of alcoholism, liver disease or advanced cirrhosis.
- Vitamin B12if neededPeripheral neuropathy.
Sources (3)
- Allen RE, Kirby KA. Nocturnal leg cramps. Am Fam Physician 2012;86(4):350-355.
- CRAMPES IDIOPATHIQUES DES MEMBRES INFERIEURS DE L'ADULTE
- Medicines and Healthcare products Regulatory Agency (MHRA, Royaume-Uni). Quinine: not to be used routinely for nocturnal leg cramps. Drug Safety Update, juin 2010 (page gov.uk publiée le 11 décembre 2014 ; avis complémentaire sur l'allongement du QT en novembre 2017).