After cancer treatment ends, you may find that you still feel tired and unable to do the things you want and need to do. Extreme tiredness is a very common problem for cancer survivors. It may last for months or even years after cancer treatment ends.

This tiredness is called cancer-related fatigue. It's different for each person. It can even be different every day. You may not have the energy to do things you used to do. Your arms and legs might feel heavy or weak. You may have trouble focusing, thinking, or remembering. Many times, this kind of tiredness doesn't get better with sleep or rest. It's not linked to recent activity, and it impacts the things you do.

Fatigue can be very upsetting. It can greatly affect a person's ability to do daily life tasks. You may feel too tired to take care of yourself or spend time with your family. It can make it hard to go back to work and be part of social activities. Cancer-related fatigue can be a daily struggle.

Researchers are working to understand more about the causes of fatigue after cancer treatment. Surgery, radiation, and chemotherapy cause fatigue. And there are a lot of other things that may cause fatigue or make it worse. Here are some of them:

• A weakened immune system
• Changes in hormone balance
• Depression
• Electrolyte problems, including changes in potassium, calcium, and sodium levels in the blood
• Kidney problems
• Liver problems
• Low red blood cell counts (anemia)
• Lung problems
• Heart problems
• Problems in the way your body digests and uses food
• Not eating or drinking enough
• Not enough sleep or not sleeping well
• Ongoing pain
• Opioid pain medicines
• Some prescription and over-the-counter medicines
• Alcohol or substance abuse
• Infections
• Arthritis
• Deconditioning or loss of muscle mass

Talk with your doctor if you have fatigue after cancer treatment. Be sure to let them know if it's getting worse.

You'll be asked things like what your fatigue feels like, if it's changed, how it affects your daily life, and what makes it better or worse. You may be asked to rate your fatigue on a scale of 0 to 10, where 0 is no fatigue and 10 is the worst fatigue.

Blood tests might be done. These can look at levels of hormones, iron, and electrolytes. They also help check for other problems, such as anemia or infection. You may also see other kinds of health care providers to find out what may be causing your fatigue. This might be a heart doctor (cardiologist) or a doctor who deals with hormone balance (endocrinologist).

Treatments may include:

• Blood transfusions, medicine, or iron supplements to treat anemia.
• A change in doses or types of medicine.
• Medicine to help control pain.
• Medicine or other ways to help you sleep better.
• Medicines to help you feel more awake during the day.
• Hormone therapy.
• Medicine to help treat depression.
• Vitamins.
• Complementary therapies such as mindfulness, yoga, or acupuncture.
• Physical therapy to help you exercise and improve muscle strength.

Don't ignore fatigue. It might be a sign of a problem that needs to be treated. And don't try to treat it yourself with vitamins, herbs, or special diets. Talk with your doctor before trying any of these things.

If you are coping with cancer-related fatigue:

• Eat a healthy diet. Ask your doctor if you should also be taking any nutritional supplements. You can also ask to speak with a dietitian.
• Drink enough water every day. Ask your doctor what your goal should be.
• Limit caffeine and sugary drinks. Reduce your intake of these. And don't have them in the evening.
• Get the rest you need. Take rest breaks and naps as needed during the day. But don't rest too much or your sleep problems at night may get worse.
• Plan your time. Use your energy on things you need or want to do.
• Get the help you need. Ask others for help doing things such as cleaning, shopping, laundry, and cooking.
• Have a routine. Go to bed and get up at the same time every day.
• Get some exercise every day. Try an activity such as walking, swimming, yoga, or riding a bicycle. This can help prevent weak muscles, and can boost your energy level. Being active can lessen fatigue and help you feel better.

It can help to talk with other cancer survivors dealing with fatigue. You may learn new ways to cope with fatigue after cancer. Talking with a counselor may also help you manage fatigue, especially if depression is making it worse. Talk with your health care team about finding a counselor, a support group, or both.