Leg muscle cramps: what to know

Cramps can follow exertion, prolonged sitting, dehydration or a muscle strain. They may also be associated with changes in thyroid function, kidney disease, vitamin D deficiency, circulation problems or reduced muscle strength. A cramp is a symptom, not a diagnosis, so its timing and accompanying features matter. Tell a clinician if cramps began after a medicine change, happen in several muscle groups, or leave lasting soreness, weakness or numbness.

Stop the activity and gently lengthen the muscle: for a calf cramp, straighten the knee and draw the toes towards the shin. Massage the area and use warmth once the muscle begins to release. Move regularly, warm up before exercise, stretch calves gently and drink fluids through the day. Avoid taking electrolyte products or supplements routinely unless a clinician recommends them for your situation.

Get urgent help if a leg becomes swollen, red, hot or persistently painful, or if cramping follows a serious injury. Emergency care is needed with chest pain, sudden breathlessness, fainting or a cold, pale limb. Arrange a medical review when cramps are frequent, severe, new after a medicine change, or accompanied by weakness, walking difficulty or reduced sensation.

Ask whether your medicines, hydration, exercise pattern or circulation could be contributing. Discuss whether blood tests or a muscle and nerve examination are appropriate, and ask which stretches or supplements are safe for you.