mamyalynne.....is quite correct.......more information needed.
Are you on any medication?
Do the cramps come on at rest or only on exercise?
let me guess...you are in your late 50's, tired, overweight and definitely female.
Two things come to mind:
1) Underactive thyroid......simple blood test will sort that out.
2) Dehydration..having the central heating on all the time due to adverse weather conditions, your body soon "dries out." Drink plenty of water.
If my assessment of your persona is incorrect, then my advice remains the same ;-)