Nutrition in Cancer Care (PDQ®): Supportive care - Patient Information [NCI] - Treatment of Symptoms
Dehydration (Lack of Fluid)
The body needs plenty of water to replace the fluids lost every day. Nausea, vomiting, and pain may keep the patient from drinking and eating enough to get the amount of water the body needs. Long-term diarrhea causes a loss of fluid from the body. One of the first signs of dehydration (lack of water in the body) is feeling very tired. The following may help cancer patients prevent dehydration:
- Drink 8 to 12 cups of liquids a day. This can be water, juice, milk, or foods that have a lot of liquid in them, such as ice pops, flavored ices, and gelatins.
- Stay away from drinks that have caffeine in them, such as sodas, coffee, and tea (both hot and cold).
- Take a water bottle whenever leaving home. It is important to drink even if not thirsty.
- Drink most liquids between meals.
- Use medicines that help prevent and treat nausea and vomiting.
It is very common for cancer patients to have constipation (fewer than three bowel movements a week). Constipation may be caused by the following:
- Too little water or fiber in the diet.
- Not being active.
- Cancer treatment, such as chemotherapy.
- Certain medicines used to treat the side effects of chemotherapy, such as nausea and pain.
Preventing and treating constipation is a part of cancer care.
To prevent constipation:
- Eat more fiber-containing foods. Twenty-five to 35 grams of fiber a day is best. Food labels show the amount of fiber in a serving. (Some sources of fiber are listed below.) Add a little more fiber each day and drink plenty of fluids at the same time to keep the fiber moving through the intestines.
- Drink 8 to 12 cups of fluid each day. Water, prune juice, warm juices, lemonade, and teas without caffeine can be very helpful.
- Take walks and exercise regularly. Wear shoes made for exercise.
To treat constipation:
- Continue to eat high-fiber foods and drink plenty of fluids. Try adding wheat bran to the diet; begin with 2 heaping tablespoons each day for 3 days, then increase by 1 tablespoon each day until constipation is relieved. Do not take more than 6 tablespoons a day.
- Stay physically active.
- Use over-the-counter constipation treatments, if needed. These include:
- Cottonseed and aerosol enemas can also help. Do not use lubricants such as mineral oil because they may keep the body from using important nutrients the way it should.
Good food sources of fiber include the following:
- Legumes (beans and lentils).
- Cold cereals (whole grain or bran).
- Hot cereals.
- Whole-grain breads.
See the Constipation section of the PDQ summary on Gastrointestinal Complications for more information.