Overview
Anaemia means the blood does not carry enough oxygen to the body's tissues, either because there are too few red blood cells or the red blood cells do not contain enough haemoglobin. It causes tiredness, paleness, and breathlessness. Iron deficiency is the most common cause worldwide.
How common is it?
Anaemia is a major global health problem, particularly affecting young children, pregnant and postpartum women, and menstruating girls and women. The burden varies between countries and population groups.
Causes and risk factors
Red blood cells can be reduced by blood loss, reduced production, or increased destruction. The cause determines the type of anaemia and guides treatment.
Common risk factors
- Low dietary iron, folate, or vitamin B12 intake
- Heavy menstrual periods
- Internal bleeding from ulcers or bowel cancer
- Pregnancy (increased iron demand)
- Chronic diseases such as kidney disease or rheumatoid arthritis
- Inherited conditions like sickle cell disease or thalassaemia
Symptoms
- Persistent tiredness and weakness
- Pale or yellowish skin
- Shortness of breath on mild exertion
- Headaches and dizziness
- Cold hands and feet
- Rapid or irregular heartbeat
- Brittle nails or hair loss (iron deficiency specifically)
When to see a doctor
Arrange assessment for unexplained tiredness, pallor, breathlessness or a known low haemoglobin result. The cause needs investigation; iron deficiency in men and post-menopausal women may reflect gut blood loss. Severe breathlessness, chest pain or collapse needs emergency help.
Diagnosis
A full blood count identifies anaemia and gives information about the size and appearance of red blood cells. Further blood tests identify the cause. Occasionally, bone marrow examination or endoscopy is needed.
Treatments
Iron supplements
Oral iron treats confirmed iron deficiency, not every type of anaemia. A clinician chooses the preparation and duration and checks response. Vitamin-C-containing food or drink may help absorption, but orange juice is not essential; consider glucose management if you have diabetes. Keep iron medicines away from children.
Treating the underlying cause
Stopping bleeding sources, adjusting medications, managing chronic disease, or addressing dietary deficiencies prevents recurrence.
Blood transfusion or intravenous iron
Intravenous iron may be considered for iron deficiency when oral treatment is unsuitable or ineffective. Blood transfusion is a different treatment, reserved for selected urgent or severe cases after clinical assessment.
Self-care and lifestyle
- Eat iron-rich foods: red meat, lentils, fortified cereals, dark leafy greens
- Pair plant iron sources with vitamin C to improve absorption
- Avoid tea and coffee with meals as they reduce iron absorption
- Cook in cast iron cookware which can add small amounts of dietary iron
Prevention
A varied diet with adequate iron, vitamin B12 and folate helps prevent nutritional deficiencies. Supplements should match individual needs, including during pregnancy. Not all anaemia is preventable. Bowel screening does not replace investigation of unexplained iron deficiency or symptoms.
Sources for targeted updates
Updated: 24 October 2026. Targeted corrections to frequency, urgent-care guidance, treatment, prevention, key facts. This update covers the named sections; a full review of the remaining guide is pending.