Fatigue with kidney cancer doesn’t always come from the cancer itself. If you’ve been feeling unusually weak, short of breath, or worn out, anemia (low red blood cells) could be part of the reason.

Kidney cancer can sometimes cause anemia, and some treatments can too. This article covers why anemia can happen with kidney cancer, symptoms to watch for, and how it may be treated.

Knowing what to watch for can help you talk with your care team and find ways to feel better.

What Can Cause Anemia With Kidney Cancer?

Anemia is a condition in which your blood does not have enough healthy red blood cells or enough hemoglobin to transport oxygen to the body’s tissues. Hemoglobin is a protein in red blood cells that oxygen attaches to.

Anemia in people with kidney cancer can often have more than one cause. It can stem from the cancer itself, effects of cancer treatment, related diseases, or other factors.

Can Kidney Cancer Itself Cause Anemia?

Yes. Kidney cancer can sometimes cause anemia. The kidneys normally make a hormone called erythropoietin (EPO) that tells the bone marrow to produce red blood cells.

If your kidney cancer affects how well the kidneys work, anemia can develop. Kidney cancer is also linked to inflammation, which can reduce red blood cell production.

What if You Also Have Kidney Disease?

Chronic kidney disease (CKD) increases the risk of developing kidney cancer, and kidney cancer can cause chronic kidney disease, so it’s not uncommon for someone to have both.

CKD raises the risk of anemia because:

• Damaged kidneys may not make enough of the hormone that helps the body produce red blood cells.
• People with CKD may be low in iron due to dialysis and reduced absorption in the intestines, and iron is needed to make healthy red blood cells.
• People with CKD may have low vitamin B12 or folate, which is also needed to make red blood cells.
• CKD can lead to chronic inflammation, interfering with the body’s use of iron.
• CKD treatments can lead to blood loss.

Do Age and Other Factors Matter?

Adults 65 and older are more likely to develop anemia for many reasons, including:

• Chronic inflammation
• Kidney disease
• Nutritional problems
• Blood loss
• Bone marrow disorders

So if you are older and living with kidney cancer, your care team may look for more than one cause.

Developing anemia may also have nothing to do with kidney cancer or CKD.

Other possible contributors include:

• Diet low in iron, vitamin B12, or folate
• Trouble absorbing nutrients (like in Crohn’s or celiac disease)
• Ongoing bleeding (like with heavy periods or an ulcer)
• Some medications
• Not taking iron and folic acid supplements during pregnancy
• Genetics and family history
• Heavy alcohol use or exposure to toxic chemicals

How Can You Tell if You Might Have Anemia?

Anemia happens when the blood doesn’t have enough red blood cells or hemoglobin to transport oxygen throughout the body efficiently. It can be mild at first, and some people don’t notice symptoms right away.

As anemia worsens, it can leave you feeling drained or short of breath doing things that used to feel routine.

Symptoms To Watch For

Symptoms of anemia may include:

• Fast or irregular heartbeat
• Cold hands and feet
• Tiredness or extreme fatigue
• Weakness
• Dizziness or lightheadedness
• Shortness of breath
• Pale skin, gums, or nail beds
• Headaches
• Chest pain, especially if anemia is more severe

Some of these symptoms overlap with kidney cancer itself and with treatment side effects. For example, fatigue can happen with kidney cancer even without anemia. That’s why symptoms alone cannot confirm the cause.

How Is Anemia Diagnosed?

If you have symptoms, your cancer care team may order a complete blood count (CBC) to check the amount of red blood cells and the level of hemoglobin in your blood.

If you do have anemia, you may need more tests to look for the cause, such as blood tests for iron or vitamin levels, tests to look for bleeding, or sometimes other studies, such as a bone marrow biopsy.

Talk to your doctor or cancer care team if you notice new symptoms of anemia, if your symptoms are getting worse, or if the symptoms are making it harder to get through your day. Your care team can check for anemia and recommend treatment that may help you feel better.

How Is Anemia Treated When You Have Kidney Cancer?

Treatment for anemia depends on the cause, how low your hemoglobin is, your symptoms, and your overall cancer plan. Treatment is important because fatigue can really affect overall functioning and quality of life.

Treatment may include a blood transfusion, medication, vitamin supplements, or adjustments to the cancer treatment strategy.

Blood Transfusions

A red blood cell transfusion may be used if your hemoglobin is very low or if you have signs of severe bleeding. Transfusions can raise red blood cell levels quickly, so they’re often used when symptoms are more severe or fast relief is needed.

Erythropoiesis-Stimulating Agents

Erythropoiesis-stimulating agents (ESAs) are medicines that tell the body to make more red blood cells. ESAs carry some serious risks, so they may only be offered to some people with chemotherapy-related anemia when treatment isn’t meant to cure the cancer (but rather prolong life).

Because chemotherapy isn’t generally used for the most common kidney cancers, ESAs would usually be considered only in the rarer cases where chemotherapy is part of treatment.

Your care team will weigh possible benefits against risks before using them.

Iron, Vitamin B12, or Folate Supplements

If testing shows that your anemia is related to low iron, low vitamin B12, or low folate, your care team may recommend supplements. Iron may be given as a pill or intravenously (through a vein). Vitamin B12 or folate may be given as a pill, shot, or through an IV.

Adjusting Cancer Treatment

If a treatment is contributing to anemia, your doctor may lower the dose, switch treatments, or pause treatment to let your body recover. Whether that makes sense depends on the type of kidney cancer, the goals of treatment, and how severe the anemia is.

Join the Conversation

On MyKidneyCancerTeam, people with kidney cancer and their loved ones come together to ask questions, share experiences, and find support from others who understand.

Have you dealt with anemia alongside kidney cancer? Share your experience in the comments below.