context: var s_context; s_context= s_context || {}; s_context['wb.modimp'] = 'vidfloat'; if(webmd.useragent && webmd.useragent.ua.type === 'desktop'){ webmd.ads2.disable Initial Load(); webmd.ads2.disable Ads Init = true; $(function() { webmd.p.pim.increment(); $('.responsive-video-container').insert After('.module-social-share-container'); require(['video2/1/responsive-player/video-loader'], function(video Loader) { video Loader.init({ autoplay: webmd.useragent.ua.type === 'desktop' && ! !s_sensitive, chron ID: $('article embeded_module[type=video][align=top]:eq(0)').attr('chronic_id'), continuous Play: true, cp Options: { flyout: true }, display Ads: true, mode: 'in-article', sticky: true }) }); }); } else { $(function(){ $('.responsive-video-container').remove(); }); } You could be out for a run or drifting off to sleep when it happens: The muscles of your calf or foot suddenly become hard, tight, and painful. You are having a muscle cramp. How can you stop it and prevent another one from happening? Sometimes called âcharley horsesâ -- particularly when they're in the calf muscles â cramps are caused by muscle spasms â involuntary contractions of one or more muscles. Almost everyone gets a muscle cramps, which come without warning. What causes them, and what can you do to relieve them? Many things can trigger a muscle cramp. They include: Poor blood circulation in your legs Working calf muscles too hard while exercising Not stretching enough Being active in hot temperatures Muscle fatigue Dehydration Magnesium and/or potassium deficiency A problem such as a spinal cord injury or pinched nerve in your neck or back Kidney disease Muscle cramps can also occur as a side effect of some drugs. Medications that can cause muscle cramps include: Furosemide ( Lasix), hydrochlorothiazide ( Microzide), and other diuretics ("water pills") that remove fluid from the body Donepezil ( Aricept), used to treat Alzheimer's disease Neostigmine ( Prostigmine), used for myasthenia gravis Nifedipine ( Procardia), a treatment for angina and high blood pressure Raloxifene ( Evista), an osteoporosis treatment Terbutaline ( Brethine), albuterol ( Proventil and Ventolin), asthma medications Tolcapone ( Tasmar), which helps treat Parkinson's disease Statin medications for cholesterol, such as atorvastatin ( Lipitor), fluvastatin ( Lescol), lovastatin ( Mevacor), pravastatin ( Pravachol), rosuvastatin ( Crestor), or simvastatin ( Zocor) For a charley horse in the calf or a cramp in the back of the thigh (hamstring), try this stretch: Put your weight on the affected leg and bend your knee slightly. Or, sit or lie down with your leg out straight and pull the top of your foot toward your head. For a cramp in the front of the thigh (quadriceps), hold on to a chair to steady yourself and pull your foot back toward your buttock. You can also massage the muscle, ice it, or try taking a bath with Epsom salt. To help stop cramps before they start: Eat more foods high in vitamins and magnesium. Stay well-hydrated. Stretch daily and before exercise. Daily stretching can help with cramps from non-exercise related causes, and stretching before exercise can help prevent tight muscles. In most cases, you can take care of a leg cramp. It will likely stop within minutes. But if you get them often and for no clear reason, tell your doctor.