What causes a “Charlie Horse” (calf cramp) and why do they happen during sleep?
What are nighttime leg cramps? Nighttime (or nocturnal) leg cramps are usually sudden spasms, or tightening, of muscles in the calf. But the muscle cramps can sometimes happen in the thigh or the foot. They often occur just as you are falling asleep or waking up. These painful cramps can last a few seconds to a few minutes. These leg cramps are also called charley horses. What causes nighttime leg cramps? Though nighttime leg cramps are common, experts don’t know exactly what causes them. But most of the time it is not because of illness. Some of the things that may cause leg cramps include: * Getting too much exercise or overusing the muscles. * Standing on concrete for a long time, sitting for a long time, or putting your legs in awkward positions while you sleep. * Not having enough potassium, calcium, and other minerals in your blood. * Being dehydrated, which means your body has lost too much fluid. * Taking certain medicines, such as antipsychotics, diuretics, statins, and steroi
