The Zoldyck family owns and lives at Kukuroo Mountain, a dormant volcano in the Dentora region of the Republic of Padokia, which stands 3,772 meters. Their estate is surrounded by huge stone walls guarded by a giant dog named Mike and attendants highly skilled in martial arts.
The position in which you sleep can cause your calf muscles to twitch severely. If you are in the habit of sleeping on one side with your knees bent at an angle, and your toes pointing straight, or downwards, there is a high probability that you may be caught unawares by cramps.
The calf is swollen and tender. To rule this out alone I would see your primary doctor. Other causes are more rare. A Baker's cyst is a common condition in which part of the joint behind the knee forms a growth. This is normally not concerning, but if it ruptures it can cause a swollen and tender calf. If this is the case, pain medicine can be given until it heals. Other causes could be from muscle inflammation--a myositis. There are many types of myositis which can be from many causes. Simple muscle inflammation from overuse is another cause--in fact the most likely. Fluid overload--from heart problem or kidney problem or liver problems can also cause swollen calves. Again these are more likely in older patients--it is possible and must be ruled out. I would see your doctor to rule out a few concerning causes of swollen calf.