Common

Leg Cramps: Causes & Prevention

Nocturnal leg cramps affect up to 60% of adults occasionally. While usually benign, frequent cramps deserve investigation for underlying causes.

Prevalence
Up to 60% of adults (occasional)
Most common time
Night, in bed
Key minerals
Magnesium, potassium, calcium
Usually
Benign but disruptive to sleep

Common Causes

CauseDetails
DehydrationReduced blood volume affects muscle function
Electrolyte imbalanceLow magnesium, potassium, or calcium
MedicationsStatins, diuretics, some asthma medications
PregnancyVery common, especially 2nd-3rd trimester
Peripheral artery diseaseCramping with walking (claudication) — more serious
Kidney disease/dialysisCommon due to electrolyte disturbances
OverexertionProlonged or unusual exercise

Blood Tests to Consider

TestPurpose
MagnesiumCommon deficiency causing cramps
PotassiumEspecially if on diuretics
CalciumDeficiency or parathyroid issues
Kidney function (eGFR)Chronic kidney disease
Thyroid (TSH)Hypothyroidism associated with cramps

Prevention Strategies

Cramping with Walking — Check CirculationIf leg pain/cramping occurs specifically with walking and eases with rest (intermittent claudication), this could indicate peripheral artery disease and should be assessed, particularly in smokers, diabetics, or those with known vascular disease.
Quick Relief During a CrampStretch the affected muscle immediately — for calf cramps, straighten the leg and pull the toes up towards the shin. Walking on the heel briefly can also help. Massaging the muscle assists relaxation.
Are leg cramps in pregnancy normal?
Yes, very common, especially in the 2nd and 3rd trimester, likely related to changes in circulation and mineral levels. Gentle stretching, staying hydrated, and magnesium supplements (if recommended by your midwife) can help.
Do quinine tablets help leg cramps?
Quinine was previously widely used but is now reserved for severe, frequent cramps due to rare but serious side effects (blood disorders). It's a prescription-only medication requiring monitoring.
Can statins cause leg cramps?
Yes — muscle aches and cramps are a recognised statin side effect. If troublesome, discuss with your doctor — a dose adjustment or switching statins may help.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.