I frequently wake up during the night with cramps in my calf. My doctor says he can’t find the cause. Can anything help me? —L.E., Franklin, Mich. 

For immediate relief, promptly break the cramp by using your hands to pull your foot toward your knee. Measures to prevent the problem depend on the cause, which is usually not found. One culprit may be either too much or too little exercise during the day, so adjusting your activity level and stretching your calf muscles regularly may help. Less often, the cramps can be a side effect of certain drugs, including the osteoporosis drug raloxifene (Evista) and several cardiovascular medications, including atorvastatin (Lipitor), fenofibrate (Tricor and generic), furosemide (Lasix and generic), hydrochlorothiazide (Esidrix and generic), and nifedipine (Procardia and generic). In rare cases, leg cramps may indicate an underlying disorder, such as diabetes, kidney failure, thyroid problems, or peripheral vascular disease, so ask if your doctor has ruled those out.