What underlying conditions should I investigate in a patient presenting with frequent leg cramps at night?

In a patient presenting with frequent leg cramps at night, the following underlying conditions should be investigated:

• Electrolyte imbalances and volume depletion, which may indicate systemic disorders such as acute kidney injury.
• Primary muscle diseases, which can be assessed by serum creatine kinase (CK-MM) and aldolase levels.
• Lower motor neurone diseases, which may require electromyography or nerve conduction studies.
• Familial causes of cramps, which might necessitate genetic studies.
• Neurological disorders if there are additional neurological symptoms or if the diagnosis is uncertain.

Referral to specialists such as neurology or rheumatology is recommended when an underlying cause is suspected that cannot be managed in primary care or if symptoms affect quality of life.

Severe cramps accompanied by altered consciousness, anuria, or abnormal body temperature warrant hospital admission to exclude serious systemic causes.

Idiopathic leg cramps are common and often do not require investigation unless the frequency, severity, or nature of cramps changes or they impact quality of life.

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