What is the cause of leg cramps while trying to sleep?

Sometimes night cramps occur without any identifiable causes, but they generally tend to represent muscle fatigue or nerve problems, according to Mayo Clinic. Known causes for night leg cramps include medications, metabolic disorders, blood vessel problems, Parkinson's disease and arthritis.

Night leg cramp causes vary widely, from insufficient potassium or calcium in the blood to dehydration, pregnancy or sleeping with the legs in awkward positions, according to WebMD. Age is generally a factor, with people over age 50 experiencing more frequent episodes, but anyone can get night leg cramps from sitting in one position for a long time or standing on concrete floors, states the Cleveland Clinic.