Radiation Therapy

Radiation Therapy: What Are The Side Effects Of Treatment?

Patients undergoing radiation therapy usually experience side effects in the areas being treated. There are often ways to treat these symptoms. Be sure to tell your doctor or nurse if you experience any of the following side effects.

Tiredness, Lack Of Energy And Fatigue

Fatigue is a common symptom of radiation therapy. But it also is sometimes the hardest to describe and the easiest to overlook. It’s common to hear patients say they have no energy. This feeling can be caused by:

  • The disease itself or its treatment
  • Lowered blood counts
  • Lack of sleep
  • Pain
  • Poor appetite

Most people begin to feel tired after the second or third week of therapy. Fatigue gradually disappears after treatment is complete. To maximize your energy:

  • Rest as much as possible during and after your course of treatments.
  • At the same time, too much rest can be troublesome. Combat fatigue with appropriate exercise. Ask your nurse or doctor about exercises that can help.
  • Prioritize! Decide which activities are most important and complete only those.
  • Tell your doctor if you are experiencing fatigue. A blood test will reveal if your blood counts are low.
  • Eat a healthy diet. A poor diet robs your body of the nutrients it needs to heal. A dietitian can help plan a healthy food program.
  • If you need help with daily chores, ask friends or family members to help out.
  • Consider joining a support group, which may help you learn how to deal with fatigue and emotional stress, which can worsen fatigue.
  • Ask your employer about ways to customize your work schedule. Consider taking time off, working part-time, or working from home if possible.

Nausea And Vomiting

Radiation treatment causes nausea and vomiting usually only if the stomach or abdomen is exposed to the treatment. Nausea and/or vomiting usually occur one or two hours after undergoing a treatment. There are other causes of nausea and vomiting that should be explored if symptoms persist.

To reduce nausea and vomiting:

  • Ask your doctor, nurse or dietitian for guidelines about which foods to eat.
  • Eat small meals.
  • Eat often and try to eat and drink slowly.
  • Avoid fried foods or those high in fat.
  • Drink cool liquids between meals.
  • Eat foods that have only a mild aroma and can be served cool or at room temperature.
  • For severe nausea and vomiting, try a clear liquid diet (broth and clear juices) or bland foods that are easy to digest, such as dry toast and gelatin.

If this problem persists, tell your doctor. He or she can prescribe an antiemetic medicine to prevent nausea.


Patients who undergo radiation therapy to the lower abdomen may experience treatment-related or disease-related diarrhea. It’s important to tell your doctor immediately if this happens to you, to minimize potentially serious complications. Medications can often help relieve symptoms.

It may be helpful to avoid these foods:

  • Dairy products, including milk and ice cream. Sometimes, yogurt, buttermilk, and other similar foods are better tolerated.
  • High-fiber foods, including raw fruits and vegetables, whole grain breads
  • Spicy foods and caffeine

There are other causes of diarrhea that should be explored if symptoms persist.

Hair Loss

Unlike chemotherapy, radiation therapy causes hair loss only in the area being treated. Higher doses usually result in more hair loss.

Hair loss is often cited as having a great impact on a patient’s psychological state. It’s important for patients to have a strong supportive environment during therapy. If you expect to have radiation therapy to the head or neck area, look for a wig that matches your hair color and style before treatment begins.

Hair will usually begin to grow back once treatment is stopped. Receiving chemotherapy at the same time as radiation therapy can affect how hair grows back. Regrowth also depends on how much and the type of radiation therapy you received.

It’s important to cover your head with a hat, scarf or turban, especially when in the sun or during cold weather.

Low Blood Counts

Radiation therapy can reduce the amounts of white blood cells in your blood, which fight infection, and platelets, which help blood to clot. Your doctor may check your blood counts during treatment. If they are low, a treatment may be delayed. Fatigue may be a symptom of low blood counts.

Mouth Problems

If you are receiving radiation to the head or neck, you may experience:

  • Mouth or throat pain
  • Lack of saliva
  • Increased cavities
  • Sores near or around dentures
  • Difficulty eating

Always talk to your doctor if you experience any or all of these symptoms.

To alleviate problems:

  • Drink plenty of water and other liquids. This will help wash out your mouth and relieve dryness. Avoid alcohol.
  • Moist, soft foods may be easier to eat.
  • Use liquid supplements if eating solid foods is too hard.
  • Practice good care for your teeth, using a fluoride toothpaste that has no abrasives and gentle flossing.
  • Keep an eye on dentures to make sure they are not creating sores where they rub on your gums.
  • If need be, your doctor can recommend medicines to alleviate throat and mouth pain.

Skin Problems

Radiation therapy can irritate your skin in the area that is treated. This irritation may last throughout treatment and should gradually improve some time after treatment ends.

You may notice your affected skin:

  • Looks red and is sore
  • Is dry and may itch
  • Is darker than your other skin

It’s important to treat your skin very gently by:

  • Using lukewarm (not hot) water and a mild soap to wash. You may need to be careful to avoid washing off the marks used to pinpoint your treatment.
  • Avoiding tight or itchy clothing
  • Asking before you use any creams, sunscreen or lotions on the area
  • Not placing hot and cold objects, such as heating pads, on the area
  • Not rubbing or scratching the area

If you are going outside in the sun, cover the sensitive area.

Nice To Know:

Moist Reaction

Some kinds of radiation therapy cause skin to develop a “moist reaction,” especially in areas where the skin folds. When this happens, the skin is wet and it may become very sore.

Tell your doctor or nurse if your skin develops a moist reaction. They can suggest ways to care for these areas and prevent them from becoming infected.

Loss Of Appetite

One of the most important ways you can keep up your energy level and help your body heal is by eating a balanced diet. But what happens if you lose your appetite?

This can happen if:

  • You receive radiation therapy in the abdominal area and feel nauseous
  • You may be fatigued and feel too tired to eat
  • You receive radiation therapy to the head or neck area, which can change the way food tastes or decrease the amount of saliva in your mouth

Your doctor will monitor your weight carefully during treatment. It’s not unusual for patients to lose a pound or two each week of treatment.

Try these steps to increase your appetite and give your body the nutrients it needs during treatment:

  • Wait one or two hours after a treatment before eating.
  • Eat small meals often and eat a variety of different foods.
  • You may feel more like eating over the weekend or earlier in the week, when the effects diminish during the break from treatment.
  • When deciding what to eat, try to eat foods high in protein and calories. Protein foods include meats, eggs, legumes, and nuts. Foods high in calories include fats (butter, oils and margarine), creamed soups, cheeses, milkshakes.
  • Nutritional bars may be appealing and supply both calories and good nutrition.
  • Relaxation techniques can help calm nervous stomachs.

If you find liquids more appealing than solid foods, try liquid supplements added to milk or other beverages you enjoy. You might want to try making a shake from fruit, yogurt, milk or other healthy foods.

Anxiety, Depression And Grief

Confronting cancer commonly causes wide-ranging feelings of anxiety, fear, nervousness, and bouts of depression and grief. Anxiety is common in cancer patients. It can be described as vague, uneasy, and unpleasant feelings of potential harm or distress.

Radiation therapy does not directly cause such distress. However, it can contribute to fatigue and change a patient’s hormone balance, which can affect your emotions.

Don’t suffer alone. Your emotional state can affect your overall health and recovery. Tell your doctor if you have feelings of hopelessness and despair. It may help to talk about your feelings and concerns with a close friend, family member, or mental health professional.

Medications are also available. Support groups allows patients to share feelings with others going through similar experiences. There may be a support group where you are being treated.

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