Skip to content
Intel Lab Diagnostics Dubai
Single Biomarker

Hemoglobin (Hb)

Oxygen-Carrying Protein

Haemoglobin is the oxygen-carrying protein in red blood cells. This test measures haemoglobin levels to detect anaemia, polycythemia, or monitor blood loss. No fasting required.

BLOOD24 HOURSNO FASTING
AEDAED95
  • Free home collection
  • Physician-reviewed report

24 Hours

Turnaround

Blood

Sample

About This Test

What the Hemoglobin (Hb) test tells you

Haemoglobin is the iron-containing protein packed inside red blood cells that binds oxygen in the lungs, carries it through the circulation, and releases it where the tissues need it. Measuring it is the most direct way of asking how much oxygen-carrying capacity your blood actually has. Because red cells are constantly being made in the bone marrow and constantly being retired, the value reflects the balance between production, survival and loss at the moment the sample was taken.

A low haemoglobin is what doctors call anaemia. It is a finding rather than a diagnosis, and its importance lies entirely in the reason behind it. Iron deficiency is the most common explanation worldwide and is often the visible end of slow, unnoticed blood loss. Deficiency of vitamin B12 or folate interrupts red cell production in a different way and produces larger cells. Chronic kidney disease reduces the hormonal signal that instructs the marrow to work; long-standing inflammation locks iron away where the marrow cannot use it; and inherited conditions such as thalassaemia or sickle cell disease alter the haemoglobin molecule itself. Each of these causes tiredness and breathlessness in much the same way, which is why the number alone never settles the question.

A raised haemoglobin is interpreted with equal care. Dehydration is the commonest reason, and it does not mean more red cells at all: the same cells are simply suspended in less plasma, so the concentration reads high. Genuine increases follow from anything that leaves the tissues short of oxygen over time, including smoking, chronic lung disease, untreated sleep apnoea and prolonged life at altitude, and less commonly from a bone marrow disorder that overproduces red cells. Your doctor will look at the red cell indices, iron studies and the rest of the blood count before deciding what a result means for you.

Sample type
Blood
Measured in
g/dL
Turnaround
24 Hours
Fasting
Not required
Best for
All ages
Why Get Tested?

Fundamental test for assessing oxygen-carrying capacity of blood. Essential in evaluating fatigue, pallor, dizziness, and monitoring conditions affecting red blood cells.

  • Detecting anaemia

    It is the primary measurement used to establish whether the oxygen-carrying capacity of your blood is reduced.

  • Explaining fatigue and breathlessness

    Persistent tiredness, pallor and breathlessness on mild exertion are among the commonest reasons this test is requested.

  • Assessing blood loss

    Heavy periods, surgery and hidden bleeding in the gut are all followed by measuring haemoglobin over time.

  • Tracking treatment response

    Once iron, vitamin B12 or folate treatment begins, repeat measurements show whether it is working.

When This Test Is Ordered

Reasons your doctor may request the Hemoglobin (Hb) test

Your doctor may order this test for any of the reasons below. Some are routine checks, others follow specific symptoms or an earlier result.

  • Tiredness, breathlessness & pallor

    • You feel persistently tired, breathless on mild exertion, or look pale.

  • Blood loss

    • You have heavy menstrual periods or another recognised source of ongoing blood loss.

  • Treatment, surgery & chronic disease

    • You are being assessed before surgery or before donating blood.
    • Iron, vitamin B12 or folate treatment has been started and its effect needs checking.
    • You have a chronic condition such as kidney disease that commonly causes anaemia.
Preparation
The short version
No prep needed.
  • Blood
  • Free home collection
  • No fasting
  • Results in 24 Hours
  1. 1
    Book any time

    No fasting window: pick any slot that suits you, online or on WhatsApp.

  2. 2
    We come to you

    A DHA-licensed nurse collects your sample at home or in the office: free home collection.

  3. 3
    Results in 24 Hours

    A physician-reviewed, easy-to-read report lands securely by WhatsApp and email.

Prep note
Physician reviewed

No fasting is required and you can take your usual medicines and supplements.

Drink normally in the hours before your appointment, because dehydration concentrates the blood and can make haemoglobin read falsely high, while a very large fluid intake can dilute it. Sit for a few minutes before the sample is taken, since standing for a long period shifts the value slightly.

If you are taking iron, vitamin B12 or folate, mention when you started, and tell the team about any recent transfusion, because donated cells will influence the result for some weeks afterwards.

Understanding Your Results

A result in the "Low" g/dL band is anaemia, which is a finding to investigate rather than a diagnosis. Iron deficiency is the commonest cause, followed by blood loss including bleeding hidden in the gut, vitamin B12 or folate deficiency, chronic kidney disease, long-standing inflammation, and inherited conditions such as thalassaemia. A "Normal" g/dL result reflects healthy oxygen-carrying capacity, though hydration shifts the figure in both directions without any change in true red cell mass. A "High" g/dL reading is more often dehydration, smoking, life at high altitude, chronic lung disease or untreated sleep apnoea than a marrow disorder. Haemoglobin alone does not reveal the cause, and thalassaemia trait can look much like iron deficiency here. Your doctor reads it with red cell indices, iron studies, your symptoms and your history, and judges recovery on the trend.

SmartReport
1217
Healthy zone15g/dLNormal
Reference ranges · g/dL
Low
Low (anaemia): may cause fatigue. Consult your physician.
5–11.9
Normal
Healthy haemoglobin level.
12–17
High
Elevated: interpret with hydration and clinical context.
17.1–22

Ranges are a guide: your physician interprets your result alongside your symptoms and history.

Reading a High or Low Result

  • What a higher result can point to

    • Dehydration, which concentrates the blood without any true increase in red cells.
    • Smoking, which raises red cell production to compensate for reduced oxygen delivery.
    • Chronic lung disease or untreated sleep apnoea, where low oxygen drives the bone marrow.
    • Prolonged life at high altitude.
    • Polycythaemia vera and other bone marrow disorders that overproduce red cells.
    • Testosterone therapy or the misuse of erythropoietin.

  • What a lower result can point to

    • Iron deficiency, the most common cause worldwide.
    • Acute or slow chronic blood loss, including bleeding hidden within the gut.
    • Vitamin B12 or folate deficiency, which disrupts red cell production.
    • Chronic kidney disease, which reduces the hormone signal driving the bone marrow.
    • Long-standing inflammation or infection, which locks iron away from the marrow.
    • Inherited conditions such as thalassaemia or sickle cell disease.

These are possibilities, not diagnoses. A single value outside the reference range is interpreted alongside your symptoms, history and other tests: your doctor decides what it means for you.

Limitations & Safety

What this test cannot tell you

  • Haemoglobin alone does not reveal the cause of anaemia; red cell indices and iron studies are usually needed alongside it.
  • Hydration shifts the value in both directions without any change in the true red cell mass.
  • Thalassaemia trait and iron deficiency can look similar on haemoglobin alone and need further tests to separate.
  • Posture and a prolonged tourniquet during sampling can nudge the value slightly.

Risks of the blood draw

  • Mild bruising or brief soreness where the needle went in.
  • Occasional lightheadedness, which settles after a few minutes of rest.
  • Bleeding or infection at the site, which is rare with sterile single-use equipment.
Key Points
  • 1Haemoglobin is the iron-containing protein that carries oxygen from the lungs to the tissues.
  • 2A low value is called anaemia, which is a finding to investigate rather than a diagnosis in itself.
  • 3A high value is more often dehydration or a response to low oxygen than a marrow disorder.
  • 4It is interpreted alongside red cell size, iron studies and the rest of the blood count.
  • 5Recovery after treatment is judged on the trend rather than on any single reading.
Related Tests
View all
Book in 60 seconds

Know your Hemoglobin (Hb).
No waiting room required.

A nurse comes to you, results land in 24 Hours, and a physician walks you through exactly what they mean.

AED95
Ask a clinician
FAQ

Frequently Asked Questions

Everything you need to know about the Hemoglobin (Hb) test. Can't find what you're looking for?

Talk to our team→

No. Iron deficiency is the most common cause, but vitamin B12 or folate deficiency, chronic kidney disease, long-standing inflammation, blood loss and inherited haemoglobin disorders all lower it too. The red cell indices and iron studies are used to tell them apart.