Accurate and timely diagnosis of iron deficiency anaemia is critical for effective treatment and the prevention of long-term complications.
Many people do not realise they are anaemic until routine blood tests show a problem. This is because the symptoms are often mild or unclear. Therefore, doctors need to stay alert, especially when patients show signs like tiredness, pale skin, shortness of breath, or changes in thinking or energy levels.
Diagnosing iron deficiency anaemia involves a full check-up, blood tests, and finding out what caused the anaemia. It’s important to remember that iron deficiency anaemia is a symptom, not a final diagnosis. Doctors must look for the real reason behind it — whether it’s diet, a disease, or blood loss — to stop it from coming back after treatment.
Clinical Checks and Early Testing
The first step in diagnosing iron deficiency anaemia is a full health history and physical exam. The doctor will ask about tiredness, dizziness, breathlessness, a racing heart, cold hands or feet, and changes like pale skin, weak nails, or hair loss. In women, menstrual history and pregnancy are also important. The doctor will also check the person’s diet, past illnesses, medicines, and family history.
During the physical check, signs such as pale inner eyelids, lips, or nails may be seen. A fast heartbeat, heart murmur, or changes in the tongue or skin may also appear. Still, these signs alone are not enough. Lab tests are needed to confirm the condition.
Blood Tests to Confirm Anaemia
The complete blood count (CBC) test is key in the diagnosis of iron deficiency anaemia. This test shows:
- Haemoglobin (Hb): Low levels confirm anaemia.
- Haematocrit (Hct): Shows the amount of red blood cells. Low levels suggest anaemia.
- Red blood cell (RBC) count: Measures the total number of red cells.
- Mean corpuscular volume (MCV): Low MCV means the red cells are small, a sign of iron deficiency.
- MCH and MCHC: These show the amount and concentration of haemoglobin in each cell. Both are usually low in iron deficiency.
- Red cell distribution width (RDW): A high RDW shows wide variation in red cell size, often an early sign.
When haemoglobin, MCV, and MCH/MCHC are all low, it usually points to iron deficiency. Still, these results don’t explain why, so further tests are needed.
Iron Studies and Other Tests
Iron studies help confirm the diagnosis of iron deficiency anaemia and rule out other causes. These include:
- Serum ferritin: Shows how much iron is stored. A level under 30 ng/mL often means deficiency. But ferritin rises during infection or inflammation, which can hide low iron.
- Serum iron: Usually low in iron deficiency.
- Total iron-binding capacity (TIBC): Often higher in iron deficiency.
- Transferrin saturation (TSAT): Shows how full transferrin is with iron. A TSAT under 20% supports iron deficiency.
Together, these tests give a clearer picture of the body’s iron levels. Low ferritin, low serum iron, high TIBC, and low TSAT confirm iron deficiency anaemia in most cases.
Additional Tools in Diagnosis of Iron Deficiency Anaemia
The reticulocyte count shows how well the bone marrow is making new red blood cells. If iron is very low, this count will also be low. A rise in this number after treatment shows the therapy is working.
Looking at blood cells under a microscope (a peripheral smear) also helps. In iron deficiency anaemia, red cells are often smaller, paler, and shaped differently. These signs support the diagnosis, especially when lab results are unclear.
Once confirmed, doctors must find out why iron is low. In men, older adults, and women who do not have heavy periods, poor diet alone is unlikely to be the cause. Extra tests may include:
- Stool tests (FOBT): To check for hidden bleeding in the gut.
- Endoscopy or colonoscopy: Useful for people over 50 or with no clear cause. These tests help find ulcers, polyps, bowel disease, or cancer.
- Coeliac disease tests: To rule out poor nutrient absorption.
- Pelvic ultrasound: For women with heavy periods, to check for fibroids.
- Helicobacter pylori test: Since this infection can affect iron absorption.
When no cause is found, a referral to a specialist may be needed.
Special Cases and Populations
In babies and children, early diagnosis is vital. Iron deficiency can affect brain development and growth. High-risk infants — such as premature babies or those only breastfed past six months — need regular checks.
Pregnant women also need regular iron tests. Their iron needs increase during pregnancy. Monitoring helps keep both the mother and baby healthy.
In athletes, especially runners, mild iron loss can occur even without anaemia. Checking iron levels can help boost energy and reduce injury risk.
Summary of Diagnosis of Iron Deficiency Anaemia
To sum up, diagnosing iron deficiency anaemia means more than spotting low haemoglobin. It involves a full review — checking symptoms, running detailed blood tests, and finding the real cause. Acting early can ease symptoms, stop future problems, and lead to full recovery. With the right tests and a careful plan, doctors can treat this condition successfully and stop it from coming back.
