Why do I read different haemoglobin values online than on my report?

Because the Netherlands measures haemoglobin in mmol/L and almost all foreign sources in g/dL. The same value therefore looks completely different: 7.5 mmol/L is about 12 g/dL, with a conversion factor of 1.61. Anyone who sets their Dutch report beside an American table compares two units and not two states of health. Always compare in the same unit, and with the band on your own report.

Is anaemia the same as iron deficiency?

No. Iron deficiency is about the store, anaemia about haemoglobin itself. The store runs out first and only then does haemoglobin fall, so iron deficiency without anaemia is common and is the stage in which you can still catch up with food. Conversely anaemia can also arise without an iron problem, through a deficiency of vitamin B12 or folate, an inflammation or blood loss.

What about anaemia in pregnancy?

In pregnancy it is mainly the blood plasma that increases, so haemoglobin dilutes and the value comes out lower by itself. That is why other, lower limits apply in pregnancy, and the midwife checks haemoglobin as standard. The need for iron rises sharply at the same time, so a low store beforehand almost always ends in a deficiency. The bands on this page apply outside pregnancy.

Anaemia

Anaemia means your blood has too little haemoglobin, the protein that carries oxygen. You often notice it as tiredness, getting out of breath quickly or a pale face. One value in your blood shows whether that is it: haemoglobin, or Hb. Anaemia is not a disease in itself but a consequence, usually of too little iron. It is also spelled anemia.

Medically reviewed by

Aäron Spapens

Lifestyle physician at Optimize

What are the symptoms of anaemia?

ComplaintEvidence
Tired and weak
Especially when you exert yourself.
strong
Out of breath quickly
On stairs or during sport.
strong
Looking pale
Less colour in your face.
strong
Dizziness
Sometimes feeling you might faint.
strong
Palpitations
You feel your heart in your chest or throat.
strong
Headache
strong
Ringing in the ears
A constant sound in your head.
strong

How strong is the evidence?

strong: In the Dutch guideline, or confirmed in several controlled trials.
fair: From one controlled trial, an international guideline or a review of research.
limited: The research does not point one way.

Evidence as of October 2026. New research can shift this.

These complaints are also described with iron deficiency, an underactive thyroid, a vitamin B12 deficiency, low testosterone.

A slowly developing anaemia can go unnoticed for a long time: the body adapts, until exertion makes the difference visible.

None of these complaints belongs to anaemia alone, and a measurement explains no complaint: the reading and the diagnosis belong with your GP. The complaint list follows the Dutch GP guideline on anaemia (NHG) and Thuisarts.nl.

See what your hemoglobin means

When is your hemoglobin too low?

Normal for women:

7.5 to 10.0 mmol/L

Your value

Enter your value as it appears on your results. Range for adults.

7.510.0

No value yet? How to get it measured

What do you do about anaemia?

Find the cause

First. Anaemia is a consequence. Your blood count shows where it comes from: small red blood cells usually point to too little iron, large ones to too little vitamin B12 or folate.

Replenish iron

With too little iron. With iron-rich food and usually iron tablets. Food alone usually does not catch up with an empty store.

Replenish the vitamin

With too little B12 or folate. With tablets, and with a severe B12 deficiency sometimes with injections.

Close the leak

At the same time. Heavy periods are the most common cause in women. Blood loss without a clear reason is worth having looked at, certainly above fifty.

Your haemoglobin is checked

After 4 weeks. If you take iron tablets. If haemoglobin does not rise, the cause has not been found yet.

The timing follows the Dutch GP guideline on anaemia (NHG).

What causes anaemia?

Too little production

Most common

The bone marrow makes fewer red blood cells than the body needs. By far the most common route.

Iron deficiency, the most common cause worldwide
A shortage of vitamin B12 or folate
Chronic disease or inflammation slowing production down
A bone marrow disorder, rare

Blood loss

More red blood cells are lost than the bone marrow can replace.

Heavy or prolonged menstruation
Bleeding in the stomach or bowel, which is not always visible
Surgery or childbirth

Accelerated breakdown

Red blood cells live shorter than the roughly one hundred and twenty days that are normal.

Haemolytic anaemia, in which the immune system breaks down its own cells
Inherited forms such as thalassaemia and sickle cell disease

How to get anaemia measured

Every value below has its own page: what is normal, and what your value means.

Which blood values show anaemia?
Value	What it shows	Points here when
Hemoglobindefining	The oxygen-carrying protein itself. The value that decides whether there is anaemia.	low

And 12 values that complete the picture

Which blood values show anaemia?
Value	What it shows	Points here when
Hematocrit	The share of red blood cells in your blood. Falls along with haemoglobin.	low
Erythrocytes	The number of red blood cells per litre.	low
MCV	The average cell size. Points to the cause: small towards iron, large towards B12 or folate.	abnormal
MCH	How much haemoglobin an average red blood cell carries.	low
RDW	How much cell sizes differ from each other. Rises when old and new cells mix.	high
Ferritin	The iron store. Low in anaemia caused by iron deficiency.	low
Vitamin B12	Low in anaemia with large red blood cells.	low
Folate	The other vitamin behind large red blood cells.	low

Also in this test

The Iron & fatigue test (€99, single test) measures the values on this page.
Every draw is fasted: nothing to eat or drink from midnight, only water. Appointments are therefore in the morning, until 12:00.
You can draw at 600+ locations near you, no referral needed. See the locations
Results within 24 hours of analysis, in the app.

What is anaemia?

Haemoglobin sits in your red blood cells and binds oxygen in the lungs, to release it where your body needs it. If haemoglobin falls, the transport capacity of your blood drops. The body catches that first: the heart pumps faster, breathing speeds up and proportionally more blood goes to the organs that ask hardest for oxygen. Precisely that compensation causes the familiar complaints, from palpitations to dizziness on standing up. The finding itself does not yet say why haemoglobin is low. For that you look at the blood count around it. MCV points the way: small red blood cells fit iron deficiency, large ones a deficiency of vitamin B12 or folate, and a normal MCV with a raised RDW fits a mixed picture. Ferritin, vitamin B12 and folate then complete the story, and the reticulocytes show whether the bone marrow is at least trying to make more. In adults iron deficiency is by far the most common cause, and that stage already exists for months before haemoglobin falls. After that come a deficiency of B12 or folate, an inflammation or chronic disease that inhibits production, and blood loss that goes faster than the bone marrow keeps up. Rare is accelerated breakdown or a bone marrow that itself makes too little.

What is anaemia confused with?

Each with the one value that tells the two apart.

Iron deficiency without anaemia

Distinguishing value: Ferritin

The store can already be empty while haemoglobin is still normal. A normal Hb therefore does not rule out iron deficiency; ferritin shows the store.

A shortage of vitamin B12 or folate

Distinguishing value: MCV

Gives the same anaemia, but MCV points the other way: red blood cells become larger instead of smaller.

Thalassaemia or carrying it

Distinguishing value: Ferritin

Here too the red blood cells are small, but the iron store is normal. A low MCV with a normal ferritin does not fit iron deficiency and has a different explanation.

Frequently asked questions

Below 7.5 mmol/L in an adult woman and below 8.5 in a man. Over this limit there is unusually broad agreement, at all four labs, and the World Health Organization draws the same line in other units: 12 and 13 g/dL. The number says there is anaemia, not why; for that you read MCV and ferritin beside it.

Often a lack of iron from blood loss you do not notice, usually in the stomach or bowel. Think of stomach problems from painkillers, a bowel polyp or bowel cancer. Next come a lack of vitamin B12, because the stomach absorbs it less well, and anaemia with a long-term illness such as kidney disease or rheumatism. If you have anaemia from iron deficiency above fifty, without heavy periods, a bowel examination usually follows.

Sources 6

1.NHG-Standaard Anemie. 2024. richtlijnen.nhg.org
2.Unilabs test directory, haemoglobin. 2026. bepalingenklapper.nl
3.Star-shl test directory, haemoglobin. 2026. star-shl.nl
4.Certe test directory, haemoglobin. 2026. bepalingenwijzer.certe.nl
5.Clinical Diagnostics test guide, Hb and MCV. 2026. clinicaldiagnostics.nl
6.Thuisarts.nl (NHG), I have anaemia. 2024. thuisarts.nl

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This page explains what a result means. It is not a diagnosis and not treatment advice. Discuss complaints or an abnormal value with your doctor.

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