What are muscle cramps?

Muscle cramps are pain in your muscles when they suddenly tighten. Muscle cramps last from a few seconds to several minutes. Muscle cramps usually come on without warning Muscle cramps are common in healthy people, especially middle-aged and older people Cramps can happen during or right after hard exercise, or while you're in bed at night Muscle cramps very rarely are a symptom of a nerve problem

What causes muscle cramps?

Common causes of muscle cramps: Harmless cramps that happen for no reason Exercise (either during exercise or right after) You're more likely to get cramps if: Your calf muscles are tight from not stretching You sit for long periods of time You don't have enough minerals ( electrolytes ) in your blood, which can happen if you take diuretics (water pills), are in your last months of pregnancy, or have problems such as low vitamin D or alcoholism You're on dialysis for kidney problems Your thyroid doesn’t make enough hormone ( hypothyroidism ) You take certain medicines

When should I see a doctor for muscle cramps?

See a doctor right away if you have muscle cramps and any of these warning signs: Cramps in your chest, arms, or belly Weakness or losing feeling in parts of your body Muscle twitches Cramps started after you lost a lot of body fluids from throwing up, sweating a lot, having diarrhea, or taking diuretics (medicine that makes you urinate [pee] more) Call your doctor in 1 to 2 days if: You frequently have leg cramps that come while walking and go away as soon as you stop Your cramps started after you began taking a new medicine You have alcoholism

How do doctors treat muscle cramps?

If your cramps are caused by another health problem, doctors will treat that problem. If your cramps are the harmless but painful kind, you can relieve them by: Stretching the muscle For example, if the cramp is in your calf, stretch your calf by pulling your toes up toward your head (the runner's stretch). <div class="multimedia__link" data-bind="component: { name: 'multimedia-link-text', params: $data }" data-popup-model="'{"ItemId":"8466093e-6594-4b88-9683-c47bf3440efc","Title":"Runner%27s%20Stretch","Description":"","ImageUrl":null,"ThumbnailUrl":"/Content/Images/Redesign/sidebar/icon_sidebar_red.png","MediaType":"table","MediaNameTranslated":"Sidebar","UniqueId":"v36831247","Placement":null,"IsInCarousel":false,"Edition":0,"ImageWidth":null,"ImageHeight":null}'" data-popup-options="'{"ListName":"TopicMultimedia","LinkText":"Runner%27s%20Stretch","CssClass":null,"LoadLocations":false,"ShowTooltip":false,"SingleItem":false,"ShowCredits":true,"ShowDescription":true,"PopupTitle":"Sidebar","ShowTitle":true,"ShowIcon":false,"ShowModalIndicator":false,"ShowTitleInHeader":false}'"> Runner's Stretch If you get a muscle cramp in your calf you can stretch the muscle by using your hand to pull your foot upward or by doing a runner’s stretch: Stand with one leg in front of the other with both heels touching the ground Place your hands on a wall for balance Gently bend the knee of your front leg until you feel a stretch in the back of your other leg Hold this stretch while you count to 30, then relax and straighten the knee of your front leg Repeat the knee bend and stretch for a total of 5 times (for each leg) Switch so that your other leg is now in front, then repeat the knee bend and stretch again

How can I prevent muscle cramps?

Gently stretch your muscles before you exercise or go to bed After you exercise, drink water and other fluids (especially sports drinks, which have electrolytes) Don’t do a lot of hard exercise right after you eat

Quick Facts

Muscle Cramps

The Manual's Editorial Staff

Last full review/revision Oct 2019| Content last modified Oct 2019

Click here for the Professional Version

Get the full details

Topic Resources

Muscle cramps are pain in your muscles when they suddenly tighten. Muscle cramps last from a few seconds to several minutes.

Muscle cramps usually come on without warning
Muscle cramps are common in healthy people, especially middle-aged and older people
Cramps can happen during or right after hard exercise, or while you're in bed at night
Muscle cramps very rarely are a symptom of a nerve problem

Common causes of muscle cramps:

Harmless cramps that happen for no reason
Exercise (either during exercise or right after)

You're more likely to get cramps if:

Your calf muscles are tight from not stretching
You sit for long periods of time
You don't have enough minerals (electrolytes) in your blood, which can happen if you take diuretics (water pills), are in your last months of pregnancy, or have problems such as low vitamin D or alcoholism
You're on dialysis for kidney problems
Your thyroid doesn’t make enough hormone (hypothyroidism)
You take certain medicines

See a doctor right away if you have muscle cramps and any of these warning signs:

Cramps in your chest, arms, or belly
Weakness or losing feeling in parts of your body
Muscle twitches
Cramps started after you lost a lot of body fluids from throwing up, sweating a lot, having diarrhea, or taking diuretics (medicine that makes you urinate [pee] more)

Call your doctor in 1 to 2 days if:

You frequently have leg cramps that come while walking and go away as soon as you stop
Your cramps started after you began taking a new medicine
You have alcoholism

Your doctor will ask about your symptoms and do a physical exam.

Sometimes, doctors will do blood tests to check for other problems that can be causing your symptoms.

If your cramps are caused by another health problem, doctors will treat that problem.

If your cramps are the harmless but painful kind, you can relieve them by:

Stretching the muscle

For example, if the cramp is in your calf, stretch your calf by pulling your toes up toward your head (the runner's stretch).

Runner's Stretch

If you get a muscle cramp in your calf you can stretch the muscle by using your hand to pull your foot upward or by doing a runner’s stretch: Stand with one leg in front of the other with both heels touching the ground Place your hands on a wall for balance Gently bend the knee of your front leg until you feel a stretch in the back of your other leg Hold this stretch while you count to 30, then relax and straighten the knee of your front leg Repeat the knee bend and stretch for a total of 5 times (for each leg) Switch so that your other leg is now in front, then repeat the knee bend and stretch again

If you get a muscle cramp in your calf you can stretch the muscle by using your hand to pull your foot upward or by doing a runner’s stretch:

Stand with one leg in front of the other with both heels touching the ground
Place your hands on a wall for balance
Gently bend the knee of your front leg until you feel a stretch in the back of your other leg
Hold this stretch while you count to 30, then relax and straighten the knee of your front leg
Repeat the knee bend and stretch for a total of 5 times (for each leg)
Switch so that your other leg is now in front, then repeat the knee bend and stretch again

Gently stretch your muscles before you exercise or go to bed
After you exercise, drink water and other fluids (especially sports drinks, which have electrolytes)
Don’t do a lot of hard exercise right after you eat

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version

Click here for the Professional Version

Merck and the Merck Manuals

Merck & Co., Inc., Kenilworth, NJ, USA is a global healthcare leader working to help the world be well. From developing new therapies that treat and prevent disease to helping people in need, we are committed to improving health and well-being around the world. The Merck Manual was first published in 1899 as a service to the community. The legacy of this great resource continues as the Merck Manual in the US and Canada and the MSD Manual in the remainder of the world. Learn more about our commitment to Global Medical Knowledge.

What are muscle cramps?

What causes muscle cramps?

When should I see a doctor for muscle cramps?

What will happen at my doctor visit?

How do doctors treat muscle cramps?

How can I prevent muscle cramps?

OTHER TOPICS IN THIS CHAPTER

ADDITIONAL CONTENT

Test your knowledge

More Content

Muscle Cramps

What are muscle cramps?

What causes muscle cramps?

When should I see a doctor for muscle cramps?

What will happen at my doctor visit?

How do doctors treat muscle cramps?

Runner's Stretch

How can I prevent muscle cramps?

Was This Page Helpful?

OTHER TOPICS IN THIS CHAPTER

Test your knowledge

Also of Interest

Merck and the Merck Manuals

Merck Manual

Leave this Site?

What are muscle cramps?

What causes muscle cramps?

When should I see a doctor for muscle cramps?

What will happen at my doctor visit?

How do doctors treat muscle cramps?

How can I prevent muscle cramps?

OTHER TOPICS IN THIS CHAPTER

ADDITIONAL CONTENT

Test your knowledge

More Content

Muscle Cramps

What are muscle cramps?

What causes muscle cramps?

When should I see a doctor for muscle cramps?

What will happen at my doctor visit?

How do doctors treat muscle cramps?

Runner's Stretch

How can I prevent muscle cramps?

Was This Page Helpful?

OTHER TOPICS IN THIS CHAPTER

Test your knowledge

Merck and the Merck Manuals