Anaemia
Also known as: anemia, iron deficiency anaemia, low haemoglobin
A haemoglobin concentration below normal (roughly under 130 g/L in men and 120 g/L in women), reducing the blood's capacity to carry oxygen.
When to seek care
Urgent care for breathlessness at rest, chest pain, fainting, or black or bloody stools; routine review for persistent tiredness and pallor.
Overview
Anaemia is a sign, not a diagnosis. Iron deficiency from blood loss or poor intake is the commonest cause worldwide; others include vitamin B12 and folate deficiency, chronic disease, kidney failure, inherited haemoglobin disorders and bone marrow failure. Finding the cause matters because in adults it can be bleeding from a bowel cancer.
Causes
- Iron deficiency: heavy periods, gut bleeding, poor diet, malabsorption, pregnancy
- Vitamin B12 or folate deficiency
- Chronic inflammation or kidney disease
- Thalassaemia and sickle cell disease
- Haemolysis
- Bone marrow disease
Risk factors
- Menstruation and pregnancy
- Vegetarian or restricted diets
- Age over 65
- Chronic disease
- Regular NSAID or aspirin use
Symptoms
What a clinician may find
- Pale conjunctivae and palms
- Fast pulse, flow murmur
- Spoon nails, sore tongue in iron deficiency
- Jaundice in haemolysis
- Numb feet and unsteadiness in B12 deficiency
Complications
- Heart failure in severe anaemia
- Poor pregnancy outcomes
- Delayed development in children
- Missed underlying cancer
Diagnosis
Full blood count with red cell size (MCV) points to the type; ferritin, B12, folate, reticulocytes and a blood film narrow it down; coeliac tests and endoscopy or colonoscopy find gut causes of iron deficiency in men and older women.
Treatment
Treat the cause; oral iron for three months after correction (or intravenous iron if not tolerated), B12 injections or folate, erythropoietin in kidney disease, transfusion only for severe or symptomatic anaemia.
Prevention
Iron-rich diet with vitamin C, treating heavy periods, iron supplements in pregnancy where advised, avoiding unnecessary NSAIDs.