Although the reason that cramps occur is not fully understood, a number of risk factors have been identified. These include:
- Imbalance of the minerals (electrolytes) involved in muscle contraction and relaxation, including magnesium, potassium, calcium and sodium. This may occur due to dietary inadequacy, but may also be a consequence of the fluid losses that occur during vomiting, diarrhoea, dehydration and excessive sweating. In other cases, diuretic medicines cause cramps by interfering with the balance of the electrolytes.
- Being in poor physical health.
- Having tight or inflexible muscles, or poor muscle tone.
- Muscle injury or fatigue.
- Wearing high-heeled shoes for long periods of time.
- Atherosclerosis (plaque in the arteries) and other conditions associated with restricted blood flow to the muscles (ischaemia).