CBC, Iron and Ferritin Test in Delhi

CBC + Iron + Ferritin Test at Home (Iron Deficiency Anaemia Panel) 

The CBC + Iron + Ferritin combination is the diagnostic standard panel for evaluating anaemia, confirming iron deficiency, and assessing the full iron status of an individual, from total circulating iron to the size of the stored iron reserve. These three tests work in sequence: the CBC identifies that anaemia is present and characterises its pattern; serum iron measures the iron actively in circulation; and ferritin reveals how much iron remains in storage. Together, they answer the clinical question that neither can answer alone.

Iron deficiency is the most common nutritional deficiency in the world. In India, it affects a disproportionately high fraction of women of reproductive age, pregnant women, children, and adolescents, as well as a significant number of adults with poor dietary iron intake, chronic blood loss, or malabsorption. The iron stores can be depleted for weeks to months before haemoglobin falls sufficiently to produce a diagnostic finding on the CBC alone. A low ferritin identifies this pre-anaemic depletion phase before symptoms become debilitating.

MAX@Home brings this panel to your home. A certified phlebotomist collects a single fasting blood sample, dispatched to a partner NABL-accredited laboratory, with your digital authenticated report delivered within 24 to 48 hours.

What the CBC ContributLowindicates Iron Assessment

The CBC does not measure iron directly, but it shows the haematological consequences of iron deficiency with considerable precision, and these consequences appear in a predictable sequence as the iron deficit worsens over time.

The stages of iron deficiency visible on CBC

Iron deficiency develops in three recognisable stages. In the first stage, iron depletion, iron stores fall (detectable as low ferritin) but haemoglobin and red cell indices remain normal. The CBC appears entirely normal at this stage; only the ferritin in the same panel reveals the problem. In the second stage, iron-deficient erythropoiesis, stores are exhausted and the supply of iron to the bone marrow falls below what is needed for normal red cell production. The RDW rises first (reflecting size variation as some new cells are smaller than existing normal ones), followed by a fall in MCH (hypochromia, cells with less haemoglobin). Haemoglobin may still be normal or low-normal. In the third stage, iron deficiency anaemia, haemoglobin falls below normal, and the full picture of microcytic, hypochromic anaemia is established: low MCV, low MCH, low MCHC, elevated RDW, and low haemoglobin.

Haemoglobin: defining anaemia severity

Haemoglobin is the defining marker of anaemia. Normal ranges are 13.5 to 17.5 g/dL for adult males, 12.0 to 15.5 g/dL for adult non-pregnant females, and 11.0 g/dL for pregnant women (WHO threshold). Mild anaemia (haemoglobin 10 to 12 g/dL in women) typically produces fatigue and reduced exercise tolerance. Moderate anaemia (haemoglobin 8 to 10 g/dL) causes more pronounced symptoms: breathlessness, palpitations, reduced concentration. Severe anaemia (haemoglobin below 8 g/dL) is a clinical emergency in most adults and requires urgent evaluation for the cause and consideration of transfusion.

MCV: characterising the anaemia type

MCV (mean corpuscular volume) is the single most useful index for pointing the clinician toward the cause of anaemia. Low MCV (microcytosis, below 80 fL) is characteristic of iron deficiency, thalassaemia, anaemia of chronic disease, and sideroblastic anaemia. Normal MCV (normocytosis, 80 to 100 fL) is found in acute blood loss, haemolysis, and anaemia of chronic disease and chronic kidney disease. High MCV (macrocytosis, above 100 fL) points toward B12 or folate deficiency, hypothyroidism, liver disease, or medications. In this panel, microcytosis on the CBC points specifically toward iron deficiency as the likeliest cause, confirmed by low serum iron and ferritin.

RDW: detecting early or mixed deficiency

RDW (red cell distribution width) measures the variation in red cell sizes within the same blood sample. In iron deficiency, the bone marrow begins producing smaller cells as iron supply falls, while pre-existing normal-sized red cells (which survive for 120 days) are still circulating; this mixture of old normal-sized cells and new small cells elevates the RDW. A high RDW alongside a low MCV is a classic early iron deficiency pattern. RDW also rises in mixed deficiency states, for example, concurrent iron and B12 deficiency, where both macrocytic and microcytic cells are present, potentially producing a normal or near-normal MCV despite active deficiency of both nutrients.

What Serum Iron Measures

Serum iron measures the amount of iron circulating in the blood bound to transferrin, the main iron transport protein. It represents the iron in transit between absorption sites, storage depots, and the bone marrow. Normal serum iron is 60 to 170 mcg/dL in adults, though reference ranges vary by laboratory and sex.

The diurnal variation of serum iron

Serum iron is highest in the morning and can fall by 30 to 50 percent by the afternoon. A sample drawn in the morning fasting state produces the most reproducible and representative result. Afternoon or post-prandial serum iron values are more variable and may be falsely low even in iron-replete individuals. This diurnal variation is one of the reasons fasting morning blood collection is recommended for this panel.

What a low serum iron indicates, and what it doesn't

Serum iron below 60 mcg/dL indicates that the circulating iron pool is depleted. This occurs in iron deficiency, but also in any state of active inflammation (infection, surgery, rheumatoid arthritis, malignancy) where inflammatory cytokines (particularly IL-6) stimulate hepcidin production, which sequesters iron in macrophages and reduces intestinal iron absorption. This means serum iron alone cannot distinguish iron deficiency from anaemia of chronic inflammation: the differential requires ferritin and, in complex cases, transferrin saturation and soluble transferrin receptor assays. In uncomplicated iron deficiency without active inflammation, low serum iron with low ferritin confirms the diagnosis straightforwardly.

What a high serum iron indicates

Elevated serum iron (above 170 mcg/dL) is seen in iron overload states, including hereditary haemochromatosis, haemolytic anaemia, sideroblastic anaemia, and excessive oral or parenteral iron therapy. Acute iron toxicity from overdose also produces dramatically elevated serum iron. In the absence of iron supplementation, a high serum iron should prompt measurement of transferrin saturation (serum iron ÷ TIBC × 100) and genetic testing for haemochromatosis mutations if the saturation exceeds 45 percent.

What Ferritin Measures

Ferritin is an intracellular iron storage protein found predominantly in the liver, bone marrow, and spleen. A small fraction of ferritin circulates in the blood, and this serum ferritin level correlates directly with total body iron stores. It is the most sensitive and specific single blood marker for assessing iron store status.

Ferritin and iron deficiency: the earliest marker

Ferritin begins to fall before serum iron, transferrin saturation, or haemoglobin show any change. A ferritin below 12 to 15 ng/mL in the absence of inflammation is virtually diagnostic of depleted iron stores, even when the CBC is entirely normal. This makes ferritin the critical early-detection marker in this panel: a patient with normal haemoglobin and MCV but a ferritin of 8 ng/mL is iron-depleted and will develop frank iron deficiency anaemia unless iron intake or absorption improves. Treating at this stage prevents symptomatic anaemia and its consequences.

Ferritin as an acute phase reactant: the inflammation confound

Ferritin is not only an iron storage marker; it is also an acute phase reactant, meaning it rises in response to inflammation, infection, liver disease, and malignancy, independent of actual iron stores. In a patient with active inflammation, a ferritin of 50 ng/mL may appear normal but may actually reflect a normal or even high inflammatory ferritin masking underlying iron depletion. The threshold for inferring iron deficiency rises to below 50 to 100 ng/mL in patients with concurrent inflammatory conditions. This is why serum iron and CBC are interpreted alongside ferritin; in a patient with low serum iron, low MCV, and a ferritin that is low-normal (20 to 50 ng/mL) with concurrent elevated CRP, iron deficiency cannot be excluded, and further investigation with transferrin saturation is indicated.

Iron overload: ferritin as a screening marker

Very high ferritin (above 1000 ng/mL in adults, though values vary by clinical context) suggests iron overload rather than deficiency. Causes include hereditary haemochromatosis, transfusion-related iron overload in patients with thalassaemia or sickle cell disease receiving repeated red cell transfusions, alcoholic liver disease, metabolic syndrome, and adult-onset Still disease. Ferritin above 300 ng/mL in men and above 200 ng/mL in women warrants evaluation for these conditions, particularly if serum iron and transferrin saturation are also elevated.

Why All Three Are Needed Together

No single marker in this panel is sufficient on its own to fully characterise iron status. The three markers complement and validate each other:

• CBC without iron or ferritin: identifies anaemia but cannot distinguish iron deficiency from thalassaemia trait, anaemia of chronic disease, or sideroblastic anaemia, all of which can produce microcytic red cells. Cannot detect the iron depletion phase before anaemia appears.
• Serum iron without ferritin and CBC: unreliable on its own because serum iron falls in both true iron deficiency and inflammation. Without ferritin to differentiate these and without CBC to assess haematological consequences, serum iron alone can be misleading.
• Ferritin without serum iron and CBC: the most sensitive single marker for depleted stores, but an isolated ferritin elevated by inflammation may mask co-existing iron deficiency. Without CBC to confirm anaemia and serum iron to assess the circulating pool, a normal or elevated ferritin in the wrong clinical context can falsely reassure.
• All three together: CBC characterises the anaemia and its severity; serum iron confirms the circulating iron pool is depleted; ferritin confirms stores are exhausted. This convergence across three independent markers gives clinicians confidence in the diagnosis of iron deficiency anaemia without additional testing in most uncomplicated cases.

Conditions This Panel Evaluates

Iron Deficiency Anaemia

Iron deficiency anaemia is the most common cause of anaemia worldwide and the most common finding on this panel in clinical practice. It results from a mismatch between iron supply and iron demand: either intake is insufficient (poor diet, poverty, vegetarian or vegan diet without adequate iron-rich plant foods), absorption is impaired (coeliac disease, post-gastrectomy, proton pump inhibitor overuse), or losses exceed intake (menorrhagia, pregnancy, gastrointestinal bleeding from peptic ulcer, NSAID use, or colon cancer). The panel confirms the diagnosis, and further workup focuses on finding the source of loss.

Pre-Anaemic Iron Depletion

Many patients have depleted iron stores detectable through low ferritin without yet meeting the haemoglobin criteria for anaemia. Symptoms at this stage - fatigue, reduced exercise capacity, poor concentration, hair loss, and restless legs - are frequently dismissed or attributed to other causes because the CBC appears normal. Identifying iron depletion from a low ferritin in this panel is clinically significant: treatment at this stage is simpler, more rapid, and prevents progression to frank anaemia with its higher symptom and cardiac burden.

Thalassaemia Trait versus Iron Deficiency: a common clinical challenge

Thalassaemia trait (minor) and iron deficiency both produce microcytic, hypochromic red cells. In thalassaemia trait, ferritin is normal or elevated (iron stores are adequate), and serum iron may be normal. In iron deficiency, ferritin is low and serum iron is low. The CBC + Iron + Ferritin panel is the first-line investigation for distinguishing these two conditions, which require very different management: iron deficiency needs iron supplementation, while thalassaemia trait needs genetic counselling and monitoring, not iron therapy.

Thalassaemia trait (minor) and iron deficiency both produce microcytic, hypochromic red cells. In thalassaemia trait, ferritin is normal or elevated (iron stores are adequate), and serum iron may be normal. In iron deficiency, ferritin is low and serum iron is low. The CBC + Iron + Ferritin panel is the first-line investigation for distinguishing these two conditions, which require very different management: iron deficiency needs iron supplementation, while thalassaemia trait needs genetic counselling and monitoring, not iron therapy.

Thalassaemia trait (minor) and iron deficiency both produce microcytic, hypochromic red cells. In thalassaemia trait, ferritin is normal or elevated (iron stores are adequate), and serum iron may be normal. In iron deficiency, ferritin is low and serum iron is low. The CBC + Iron + Ferritin panel is the first-line investigation for distinguishing these two conditions, which require very different management: iron deficiency needs iron supplementation, while thalassaemia trait needs genetic counselling and monitoring, not iron therapy.

Iron Overload: Haemochromatosis

Hereditary haemochromatosis, caused by mutations in the HFE gene, most commonly C282Y, causes progressive iron accumulation in the liver, heart, pancreas, joints, and skin, eventually leading to cirrhosis, diabetes, arthropathy, and cardiomyopathy. On this panel, haemochromatosis presents as elevated serum iron and elevated ferritin, often with normal haemoglobin. Early identification allows therapeutic phlebotomy to reduce iron burden before organ damage occurs. The combination of high ferritin and high serum iron in a patient without inflammatory disease or recent transfusions is a significant finding that should prompt measurement of transferrin saturation and HFE genetic testing.

Anaemia in Pregnancy

Pregnancy dramatically increases iron requirements, from 18 mg per day in non-pregnant adults to 27 mg per day in the second and third trimesters, because the mother is supplying iron for foetal haemopoiesis and placental function while simultaneously expanding her own red cell mass. Iron deficiency is the most common cause of anaemia in pregnancy and is associated with preterm birth, low birth weight, and postpartum haemorrhage. This panel is appropriate for initial anaemia evaluation in pregnant women, with the caveat that ferritin interpretation must account for the physiological fall in ferritin that occurs even in iron-replete pregnancies from plasma volume expansion.

Who Should Get This Test

• Women of reproductive age with heavy or prolonged menstrual bleeding, fatigue, or hair loss.
• Pregnant women being evaluated for anaemia at any stage of pregnancy.
• Vegetarians and vegans with inadequate dietary iron intake or those who have never had iron stores assessed.
• Children and adolescents with growth impairment, fatigue, or learning difficulties.
• Athletes, particularly endurance athletes, who are at risk for sports-related iron depletion from foot-strike haemolysis and increased iron losses through sweat.
• Patients with gastrointestinal conditions (coeliac disease, inflammatory bowel disease, post-bariatric surgery) with malabsorption affecting iron uptake.
• Blood donors who donate frequently and need monitoring to confirm iron stores are adequate between donations.
• Patients with symptoms of iron overload or a family history of haemochromatosis.

How to Prepare for the Test

Fasting and timing

Fasting for eight to ten hours is recommended before this test. Serum iron shows pronounced diurnal variation and is highest in the morning in the fasting state; a morning fasting collection gives the most reproducible result and avoids any post-prandial confounders. CBC is not significantly affected by food intake but is also best collected under consistent conditions. Water may be consumed freely.

Iron supplementation and medication notes

• If you are currently taking iron supplements: do not take your iron tablet on the morning of the test before the blood draw. A dose taken immediately before collection will transiently elevate serum iron without reflecting steady-state absorption and stores.
• If you have recently received an intravenous iron infusion: inform your doctor, as serum ferritin rises dramatically after IV iron administration and takes four to eight weeks to reflect the new storage equilibrium. Testing immediately after IV iron gives misleadingly high ferritin values.
• Inform the phlebotomist if you have had a recent blood transfusion, as transfused red cells significantly affect the CBC and both serum iron and ferritin temporarily.

How to Book with MAX@Home

Booking a CBC + Iron + Ferritin home test with MAX@Home is straightforward.

1.  Visit the MAX@Home website or call the helpline and select the CBC + Iron + Ferritin panel.

2.  Choose a morning fasting appointment for the most reliable serum iron reading.

3.  A certified phlebotomist arrives at your home at the scheduled time with all sterile collection equipment.

4.  A single venous blood draw provides the sample for all three components.

5.  Samples are transported under appropriate conditions to a partner NABL-accredited laboratory.

6.  Your digital authenticated report is delivered within 24 to 48 hours to your registered email or phone.