Can chemotherapy cause anaemia in cancer?

Red blood cells carry oxygen around the body using haemoglobin. Many chemotherapy medicines affect rapidly dividing cells, including blood-forming cells in the bone marrow. Anaemia may develop when the body makes fewer red blood cells. Cancer-related inflammation, bleeding, nutritional deficiency, kidney problems, or other medicines may also contribute, so chemotherapy is not always the only explanation.

Possible symptoms include tiredness, reduced stamina, dizziness, headaches, breathlessness with activity, paleness, or a faster heartbeat. Symptoms can overlap with the effects of cancer and treatment. A blood test, including the haemoglobin level and other blood-cell measures, helps the team assess the pattern and severity.

Tell your cancer team about new fatigue, dizziness, breathlessness, palpitations, or reduced ability to carry out usual activities. Do not start iron, vitamins, or herbal products without checking first; they may not address the cause and can interfere with care. The team may review your medicines, look for bleeding or deficiencies, and repeat blood tests.

Management depends on the cause and symptoms. Options may include treating a deficiency or bleeding source, adjusting the treatment plan, giving a red blood cell transfusion when clinically needed, or considering medicine that supports red blood cell production in selected situations. Your team will explain the benefits and drawbacks of the option proposed.

Seek urgent medical help for breathlessness at rest, chest pain, fainting, new confusion, a very fast or irregular heartbeat, or bleeding that does not stop. Contact the oncology team promptly for rapidly worsening weakness, black stools, blood in vomit or urine, or a new severe headache.

Ask what your blood results show, whether chemotherapy is the main contributor, and whether bleeding, kidney function, inflammation, or nutrient levels need checking. Ask how symptoms will be monitored, whether treatment timing may change, and which signs should lead you to call the team between appointments.