Up to 60 percent of North American adults suffer from night-time leg cramps, a sudden painful contraction usually of the calf muscles that can last from a few seconds up to 10 minutes or more. Doctors do not know what causes most cases of leg cramps, but usually, they are not caused by dehydration or lack of minerals.
The leading theory is that most leg cramps come from the lack of a normal nerve reflex that causes a muscle fiber to relax when it is held in contraction. That is why people who suffer recurrent leg cramps should be checked for conditions that can cause nerve damage such as vitamin B12 deficiency or diabetes.
