(HealthDayNews) -- If leg cramps wake you during the night, there's no cause for alarm.

In most cases, the spasms are innocuous and are caused by simple muscle fatigue or an imbalance of chemicals such as sodium, potassium, phosphorous, calcium and magnesium in the blood, according to Calgary Health Region in Canada.

Night-time cramps usually subside by themselves, but sometimes applying heat, massaging the leg or stretching the muscle by pulling your toes up toward you will help.

If you get cramps while you are pregnant or after you've been sweating heavily, you should talk to your doctor.