MedDroidSymptom guide
Muscle cramps: causes, warning signs & what to do
Written & medically reviewed by Dr. Sanjay Anbu, MBBS · Last reviewed
Medically reviewedA muscle cramp is a sudden, painful tightening, often in the calf at night. Most cramps are harmless; frequent cramps can point to low minerals, medicines or circulation problems.
Possible causes
Common causes of muscle cramps
- Overuse, long standing, or exercise in the heat
- Dehydration and sweating
- Low potassium, magnesium or calcium
- Pregnancy, and normal ageing
- Medicines such as water tablets (diuretics) and some cholesterol medicines
- Underactive thyroid, kidney disease or narrowed leg arteries
Self-care
What you can do now
- Gently stretch and massage the muscle — for a calf cramp, pull the toes up towards you
- Drink enough fluids, especially in hot weather or after exercise
- Stretch your calves before bed
- Do not stop any prescribed medicine on your own — ask your doctor if you think it is the cause
Red flags
When to see a doctor urgently
- Dark, cola-coloured urine with muscle pain and weakness — seek urgent care
- Cramps with weakness, numbness or muscle wasting
- One calf swollen, warm and painful (possible clot) — seek urgent care
- Leg pain on walking that eases with rest
Checks
Tests a doctor may suggest
Depending on your history and examination, a doctor may suggest some of these. Your doctor decides which, if any, you need.
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Related pages
References
Sources & further reading
Frequently asked questions
Why do I get leg cramps at night?
Night cramps are common and often have no serious cause. Tired muscles, dehydration, low minerals, pregnancy and some medicines can contribute.
Which deficiency causes muscle cramps?
Low potassium, magnesium or calcium can cause cramps. Vitamin D deficiency can cause muscle aches. A blood test can check these.
How do I stop a cramp quickly?
Stretch the muscle gently and hold it. For calf cramps, pull your toes towards your shin or stand and push your heel down.