Cancer treatment side effect: Dehydration

Do you feel thirstier than usual? Are you experiencing dry lips or skin? These may be signs of dehydration.

Dehydration is a common side effect of cancer treatment. Chemotherapy and radiation treatment can cause dehydration due to other side effects, like fevers, vomiting, diarrhea or excessive urniation.

These treatments can increase the need for IV hydration due to increased fluid needs. Dehydration also can result from exposure to excessive heat, sweating, not consuming enough fluids, medication side effects or the cancer itself.

To learn more about dehydration in cancer patients, we spoke with senior clinical dietitian Debra Ruzensky. Here’s what she had to say.

What is dehydration?

Dehydration occurs when your body loses more fluid than it takes in. Our bodies are nearly 60% water, so water is our lifeblood.

Why is staying hydrated important for cancer patients?

Fluids carry nutrients to cells, flush bacteria from the bladder and prevent constipation. Staying hydrated makes treatment side effects less severe and lowers your chances of missing or delaying cancer treatments. It also means fewer trips to the emergency room for hydration through an IV.

If it’s not addressed, dehydration can lead to severe complications, such as seizures, swelling of the brain, kidney failure, shock, coma and even death.

Since dehydration can stop normal body functions and be quite dangerous, staying hydrated during treatment is important for protecting your organs from long-term damage.

What are the signs of dehydration?

There are a few signs that you might be dehydrated. These include:

  • feeling thirsty
  • experiencing dry mouth, lips, gums, and nostrils 
  • increased headaches
  • dizziness
  • confusion
  • sleepiness
  • decreased energy
  • darker urine color and decreased urination
  • decreased skin elasticity
  • low blood pressure
  • increased body temperature

What should patients do if they have any of these symptoms? 

If you experience symptoms of dehydration, contact your care team immediately to prevent serious complications. If you’re able, increase your fluid intake a little bit at a time and keep track of what you’re drinking.

What options are there to address dehydration? And how long does it typically take for these to start working?

Once you’re dehydrated, IV hydration may be needed, especially during cancer treatment.

IV fluids can take hours to administer. The more dehydrated you are, the longer it takes for these fluids to work.

If you can drink fluids orally, it’s highly recommended that you do so throughout the day. This is easier than having to receive hydration through an IV. 

What can cancer patients do to avoid their chances of becoming dehydrated?

Each of us has different fluid needs as our bodies change. For cancer patients, fluid needs depend on many factors, such as the type of cancer treatment you’re undergoing, and whether you are dealing with a fever, diarrhea, vomiting or other gastrointestinal side effects. 

Your fluid needs are also affected by the type of cancer you have. Patients with gastrointestinal cancers, for instance, are prone to dehydration due to loss of appetite and other stomach issues caused by the cancer.

It’s important to have a dietitian calculate your fluid needs for you. MD Anderson patients can request a referral to one of our clinical dietitians, who can recommend goals not just for fluids, but also for calories and protein during treatment.

Tracking your fluid intake with a log is a great way to make sure you are meeting your individual needs so you can reduce your risk of dehydration.

What can cancer patients eat and drink to stay hydrated?

Water is best when it comes to hydrating. If you don’t like to drink water, flavored waters or waters infused with fruit or vegetables can make your water taste better.

You can also get some of the fluid you need from other beverages like milk, sports drinks, tea, coffee, and moist foods like soup, jello, yogurt, sherbet, and pudding.

Is it possible to become too hydrated?

In rare cases, overhydration or water intoxication can occur. Sodium and other electrolytes become diluted and dangerously low, causing the body to shut down.

To avoid overhydration, space out your fluid intake throughout the day. Try not to drink a lot of fluids in a short time.

What’s your advice for caregivers supporting cancer patients facing dehydration?

Have a variety of fluid sources on hand. A patient’s preferences and taste often change during treatment.

Encourage fluid intake throughout the day. Patients sometimes need a gentle nudge. 

And remember, keep yourself hydrated so you can continue to take care of your loved one.

Request an appointment at MD Anderson online or by calling 1-877-632-6789