1 If you are pregnant and have never had chickenpox, and you get chickenpox during the:  First half (about 20 weeks) of your pregnancy, there is a very slight risk (0.4% to 2%) for birth defects or miscarriage.
Certain medications can also cause leg cramps. These include: 1  High blood pressure drugs. 2  Statins to treat high cholesterol. 3  Medications for chronic obstructive pulmonary disease (COPD).
1 It is found in whole grains, spinach and other leafy green vegetables. A deficiency in magnesium can cause painful leg cramps, migraines, and also insomnia.  Potassium: Potassium is another important mineral, the lack of which can cause fatigue, muscle tightness, and cramping.