Introduction
Anaemia history is common in GP, medicine, and haematology OSCE stations. You must elicit symptoms of anaemia, then systematically narrow the cause by type. The most important clinical skill is identifying which red flag symptoms point to an underlying malignancy.
💎 Clinical Pearl
Open with: "Have you been feeling more tired than usual?" Fatigue is the universal symptom of anaemia but is non-specific — always ask what the patient attributes it to, then systematically find the cause.
Symptoms of Anaemia
🧠 Mnemonic
FAST PALE:
Fatigue and lethargy
Angina on exertion (reduced oxygen delivery to myocardium)
Shortness of breath on exertion
Tachycardia and palpitations
Pallor (conjunctival, palmar creases)
Ankle oedema (high-output cardiac failure in severe anaemia)
Lightheadedness and dizziness
Exertional syncope or presyncope
Determining the Cause — Three Key Questions
1. Is There Blood Loss?
| Source | Questions to ask |
|---|---|
| GI bleeding | Melaena (black tarry stool), haematochezia (fresh rectal blood), haematemesis, change in bowel habit |
| Menstrual loss | Heavy periods (menorrhagia): pad/tampon count, flooding, clots, duration |
| Urinary | Haematuria (visible or non-visible) |
| Other | Haemoptysis, epistaxis, easy bruising |
⚠️ Red Flag
Iron deficiency anaemia in a man of any age or a post-menopausal woman requires exclusion of GI malignancy until proven otherwise. Ask about melaena, change in bowel habit, rectal bleeding, and weight loss.
2. Is There Dietary Deficiency or Malabsorption?
| Nutrient | At-risk groups | Malabsorption causes |
|---|---|---|
| Iron | Vegetarians, vegans, pregnant women, adolescents | Coeliac disease (duodenum), gastrectomy, achlorhydria (omeprazole) |
| B12 | Strict vegans, elderly, gastric surgery patients | Pernicious anaemia (autoimmune — anti-intrinsic factor antibodies), Crohn's (terminal ileum) |
| Folate | Poor diet, alcoholics, pregnant women | Coeliac disease, methotrexate (folate antagonist), anticonvulsants |
3. Is There Haemolysis?
- Family history of haemolytic anaemia: sickle cell, hereditary spherocytosis, G6PD deficiency
- Recent infections triggering haemolysis (G6PD + infections, autoimmune haemolytic anaemia post-viral)
- Dark urine (haemoglobinuria)
- Jaundice
- Splenomegaly
Type-Specific Questions
Iron Deficiency Anaemia
- Diet: red meat intake, vegetarian or vegan, iron-rich food consumption
- Pica: craving for ice (pagophagia), clay, or soil — pathognomonic for iron deficiency
- Koilonychia (spoon-shaped nails), angular stomatitis, glossitis
- Symptoms of GI pathology: dysphagia (Plummer-Vinson syndrome), abdominal pain, weight loss, change in bowel habit
B12 and Folate Deficiency (Megaloblastic Anaemia)
- Neurological symptoms of B12 deficiency: subacute combined degeneration of the spinal cord
- Paraesthesia (tingling in hands and feet — peripheral neuropathy)
- Unsteady gait (posterior column loss)
- Memory problems and cognitive decline
- Visual disturbance
- Note: folate deficiency does NOT cause neurological features
- Autoimmune history: pernicious anaemia is associated with type 1 diabetes, autoimmune thyroid disease, vitiligo
Anaemia of Chronic Disease
- Any known chronic inflammatory, infective, or malignant condition
- Rheumatoid arthritis, SLE, chronic kidney disease, cancer, HIV
Drug History
| Drug | Effect |
|---|---|
| NSAIDs | GI bleeding causing iron deficiency |
| Methotrexate | Folate antagonist — megaloblastic anaemia |
| Anticonvulsants (phenytoin, phenobarbital) | Folate deficiency |
| Colchicine | B12 malabsorption |
| Proton pump inhibitors | Reduced acid = reduced iron and B12 absorption |
| Chemotherapy | Bone marrow suppression |
Red Flags Requiring Urgent Investigation
⚠️ Red Flag
- Iron deficiency in a man or post-menopausal woman = GI malignancy until proven otherwise
- New B12 deficiency without clear dietary cause in an older patient = GI malignancy (gastric cancer causing pernicious anaemia)
- Anaemia + weight loss + night sweats = haematological malignancy (lymphoma, leukaemia) or solid tumour
- Rapidly worsening anaemia = haemolysis, acute blood loss, aplastic anaemia
"How do you differentiate iron deficiency from B12 deficiency anaemia in the history?"
Iron deficiency presents with fatigue, pallor, and symptoms of the underlying cause (GI bleeding, menorrhagia, poor diet). Specific features include pica (craving for ice), koilonychia, and angular stomatitis. B12 deficiency presents with fatigue plus neurological features: peripheral paraesthesia (tingling in hands and feet), unsteady gait, and cognitive decline. Folate deficiency gives the same blood picture as B12 deficiency but without neurological features.
"Why is iron deficiency anaemia in a man a red flag?"
Men do not have physiological iron losses from menstruation, so iron deficiency anaemia in a man is almost always pathological. The most important cause to exclude is GI malignancy (gastric cancer, colorectal cancer) causing occult blood loss. Other causes include peptic ulcer disease and coeliac disease. All male patients with iron deficiency should be investigated with upper and lower GI endoscopy unless a clear dietary cause is established.
"What is pernicious anaemia and how does it cause B12 deficiency?"
Pernicious anaemia is an autoimmune condition in which autoantibodies destroy gastric parietal cells and attack intrinsic factor (IF). Intrinsic factor is essential for B12 absorption in the terminal ileum — without it, dietary B12 cannot be absorbed regardless of intake. It is associated with other autoimmune conditions (type 1 diabetes, autoimmune thyroid disease). Treatment is lifelong intramuscular B12 injections.
"What are the neurological features of B12 deficiency?"
B12 deficiency causes subacute combined degeneration of the spinal cord, affecting the posterior and lateral columns. Clinical features include: peripheral neuropathy (glove-and-stocking paraesthesia), loss of proprioception and vibration sense (posterior column), spastic paraparesis (lateral corticospinal tract), unsteady gait, and cognitive decline or dementia. These features do not occur with folate deficiency.
Related guides: Blood Results Interpretation OSCE | Haematuria History OSCE | Jaundice History OSCE