Hemoglobin and Cancer: How Are They Linked?

Medically Reviewed By: Jean M. Connors, MD

What is hemoglobin? 

Hemoglobin is an essential protein in your red blood cellsthat carries oxygen to your body’s organs and tissues and transports carbon dioxide from your organs and tissues back to your lungs. 

Is hemoglobin affected by cancer? 

Anemia is essentially a blood condition marked by a low level of hemoglobin and red blood cells, and in some cases can be an indication of leukemia and lymphoma. Cancers that involve the marrow space, such as leukemia or lymphoma, compete with the marrow’s function and interfere with normal red blood cell production. This, then, causes anemia. 

Other cancers that can lead to low hemoglobin include gastrointestinal cancers like stomach or colon cancer; because these cancers sometimes cause bleeding, the body may lose red blood cells faster than it can produce them. 

Kidney cancer can interfere with the hormone that tells the bone marrow to make red blood cells, potentially leading to low hemoglobin. Any cancer that metastasizes to the bone marrow can affect the amount of red blood cells made there. 

In other cases, anemia can be caused by chemotherapy or radiation treatments. 

What type of cancer causes high hemoglobin? 

While low hemoglobin levels are more often linked with cancer, some cancers can actually raise hemoglobin counts. This includes kidney cancer, liver cancer, and polycythemia vera — a rare type of blood cancer. 

Are there other conditions that can cause low hemoglobin? 

A variety of non-cancerous conditions can cause the body to produce fewer red blood cells than normal. These include chronic kidney disease, cirrhosis, hypothyroidism (underactive thyroid), inflammatory bowel disease, lead poisoning, and rheumatoid arthritis. 

Other disorders can cause the body to destroy red blood cells faster than they are produced. These include an enlarged spleen, sickle cell anemia, and thalassemia. Low hemoglobin counts can also result from bleeding in the digestive tract, as from ulcers or hemorrhoids. 

What does it feel like to have low hemoglobin? 

A low level of hemoglobin is generally 135 grams or less of hemoglobin per liter of blood, depending on your sex assigned at birth. Often in the US, the hemoglobin is reported as 13.5 gm/dl. 

A person who is anemic may experience symptoms including: 

  • Elevated pulse 
  • Shortness of breath especially with activity 
  • Dizziness or lightheadedness 
  • Chest pain 
  • Fatigue or tiredness 

Anyone experiencing these symptoms should seek medical care 

Anemia can also make your heart work harder, which may exasperate any existing heart conditions. 

Severe anemia can also result in a delay in cancer treatment or a reduction in treatment dose. If you are a cancer patient, your care team will help develop the best treatment strategy with you in accordance with your overall health. 

How can you test hemoglobin levels? 

A physician can determine the amount of hemoglobin in your blood by completing a complete blood count (CBC) test, which involves taking a sample of blood. 

Once this is determined, you doctor may perform other tests to determine what is causing elevated or lower hemoglobin. To check your organ function and vitamin and mineral levels, a blood chemistry test may be performed. 

Another test, called a reticulocyte count test, shows how many new red blood cells your body is producing. This is important because these cells carry oxygen throughout your body and transport carbon dioxide back to your lungs. If needed, a bone marrow biopsy can also be used to diagnose a variety of conditions, including anemia; blood-related cancers such leukemia, lymphoma, multiple myeloma, myelodysplastic diseases, and Waldenström’s Macroglobulinemia; certain non-cancerous blood disorders; infections that start in the bone marrow; and cancers that have spread to the bone marrow from elsewhere in the body. 

Your doctor will work with you to determine which, if any, tests you may need. 

How are high or low hemoglobin levels treated? 

Anemia is usually treated based on the cause. Your physicians will aim to treat the cause of the anemia and raise your hemoglobin level to alleviate symptoms. 

Treatment for anemia in patients with cancer will usually involve iron therapy, red blood cell transfusions — commonly known as blood transfusions — and can involve the use of erythropoiesis-stimulating agents (ESAs) such as Procrit, Epogen, or Aranesp.