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Managing Cancer Care

Leg Cramps

Cancer and its treatment may cause leg cramps and other types of muscle cramps.  Cramps or spasms are painful tightening of the muscles in the leg, ankle, or foot.

What causes leg cramps?

Some causes of leg cramps in people who have cancer include:

  • Certain chemotherapy, targeted therapy, and immunotherapy medicines
  • Radiation therapy to the lower extremities (hips, legs, etc)
  • Some hormone treatments (tamoxifen or raloxifene)
  • Medicines to treat bone loss
  • Tumors that start in a muscle or press on a muscle
  • Having too many white blood cells
  • Getting treatment for too few white blood cells
  • Staying in bed or being inactive for longer than usual
  • Overuse of certain muscles
  • Changes in the temperature around you (too hot or too cold)
  • Peripheral neuropathy or other nerve damage
  • Dehydration
  • Changes in electrolyte (blood chemistry) levels, especially phosphorus, calcium, glucose (sugar), or potassium
  • Non-cancer health problems

What to look for

  • Sudden pain or discomfort in a leg or foot and a tight or stiff muscle
  • Trouble moving the foot, or pain when moving the foot or leg
  • Changes in your quality of sleep if leg cramps happen at night.

Managing leg cramps

Your cancer care team can help create a plan to manage leg cramps. They might want you to take mineral and vitamin supplements if there is a problem with your electrolytes on a lab test. They might also prescribe a muscle relaxant if your leg cramps are severe or frequent. Your cancer care team may also suggest that you do stretching exercises or gentle exercise if you have trouble with leg cramps at night.

What you can do

  • Tell your cancer care team if you are having leg cramps. Tell your team when they happen, how long they last, what they keep you from doing, what helps, what doesn't help.   
  • Drink fluids throughout the day to prevent dehydration.
  • Apply heat or cold to cramping area when legs cramp.
  • Avoid alcohol and caffeine.
  • Keep warm and change position often.
  • If you spend most of your time in bed, try propping the covers up or using a bed cradle to protect the legs and feet from the weight of the blankets. A bed cradle is a support at the end of the bed that holds the sheets and blankets up off the legs and feet.
  • Exercise your legs by bending and straightening them several times throughout the day. A caregiver can help move your legs for you if you can’t.
  • Gently stretch your leg muscles before lying down.
  • Massage your leg, if it’s OK with your cancer care team.
  • When you have a cramp, sit up or stand up to stretch the tight muscle as much as you can without hurting it. For example, for a calf muscle cramp, try pointing the toes upward toward the knees, or walk around.

What caregivers can do

  • Help your loved one gently stretch the tight muscle.
  • Use a heat or cold pack to gently rub the cramped muscle. Ask the cancer care team which they think would be most helpful.  
  • If medicines are prescribed for cramping, be sure they are taken as directed. Watch your loved one in case they become dizzy or unsteady.
  • Contact the cancer care team if your loved one has cramping that’s not relieved by cold, heat, massage, or by stretching the cramped muscle.

Call the cancer care team right away if your loved one

  • Has a cramped leg that becomes red, swollen, hard, tender, or warm.
  • Has pain in the chest, arm, back, shoulder, or jaw, or sudden coughing, increased heart rate or is feeling light-headed. This can be an urgent problem and you might need to go to the nearest emergency room.
  • Has cramping that lasts for more than 6 to 8 hours.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

National Comprehensive Cancer Network (NCCN). Palliative care. Version 2.2023. Accessed November 29, 2023 at

Winkelman J. Nocturnal leg cramps. In: Post TW, ed. Uptodate. Uptodate; 2022. Nocturnal leg cramps - UpToDate

Last Revised: March 29, 2024

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