What is ESR (sedimentation rate)?
Red blood cells normally repel each other and sink only slowly in a standing tube. With inflammation that changes. Your liver then makes extra proteins, especially fibrinogen, and your immune system makes extra antibodies, and those proteins cancel the repulsion: the cells stack like rolls of coins and sink as clumps much faster than as single cells. The sedimentation rate measures that speed, in millimetres per hour. It is an indirect measurement: not the inflammation itself, but how much sticky protein is circulating in your blood. Those proteins come and go slowly. Fibrinogen has a half-life of days, antibodies of weeks, and that is why the sedimentation rate only rises days after the start of an inflammation and stays raised for weeks after recovery. CRP, which rises within hours and falls within days, tells what is happening now; the sedimentation rate tells what has happened in the past weeks. It also rises without inflammation: with age, because the proteins in your blood change, in women, with anaemia, because fewer cells sink faster, and in pregnancy. Your report shows the sedimentation rate in mm/hour. Normal for a man up to age 50 is about 1 to 10 mm/hour and for a woman up to age 50 1 to 15 mm/hour, where the labs overlap; from age 50 the band runs to 15 mm/hour for a man and to 20 mm/hour for a woman.
Why is ESR (sedimentation rate) relevant?
The sedimentation rate is the broad, slow gauge of inflammation, and exactly that slowness makes it useful. Anyone who has had vague symptoms for weeks, is tired, losing weight, has painful joints or muscles, and a CRP that is only slightly raised, sees in a high sedimentation rate that something has been going on for a while. In inflammatory rheumatism, in an inflammation of the blood vessels in older people that gives headache and stiff shoulders, and in some infections that run insidiously, the sedimentation rate is higher than the CRP suggests, and that difference is a clue in itself. A second reason is that the sedimentation rate measures antibodies. With a proliferation of antibody cells in the bone marrow, which occurs mainly over sixty, the blood fills with one type of antibody, and the sedimentation rate rises to far above a hundred while CRP can be normal. A sedimentation rate that high without an infection, certainly with anaemia, bone pain or a kidney working less well, is the reason to look at that. For anyone who is healthy and feels well, the sedimentation rate is mainly a value to see low and then leave alone. It says nothing about vascular risk that CRP does not say better, it rises by itself with the years, and a slightly raised value without symptoms and with a normal CRP is, in a woman over fifty, usually just her age.
ESR (sedimentation rate) reference ranges
What counts beside the number:
- CRP from the same draw, because the two move on a different timescale and the difference is a clue in itself
- Your age and sex, which determine which band applies to you; over fifty it sits higher for everyone
- Haemoglobin, because anaemia lifts the sedimentation rate without inflammation
- Whether you are pregnant, and whether you were ill in the weeks before
- How long your symptoms have lasted, because the sedimentation rate tells what has happened in the past weeks
- With a value above a hundred: haemoglobin, kidney function and the proteins in your blood
Which band applies to you depends on your sex, your age and the lab that processed your test, and over fifty the labs diverge the furthest. The national table sits wider than the labs: up to and including age 50 less than 15 mm/hour for a man and 20 for a woman, above that less than 20 and 30. The sedimentation rate moves slowly: at the start of an inflammation it takes days before there is enough protein in the blood to lift it, and after recovery it stays raised for weeks. A low value is healthy at every age.
What Dutch labs actually use
All four labs print a wider band for a woman than for a man, and three of the four widen it further from age 50. Clinical Diagnostics does not: it keeps a woman on 1 to 20 mm/hour at every age, where from age 50 Unilabs stretches her band to 25 mm/hour and Star-shl and Certe to 30 mm/hour. An ESR of 24 mm/hour is therefore called normal by three of these labs and raised by the fourth in a woman over fifty, with nothing about her blood having changed. Certe moreover writes its bands one-sided, with no lower bound, where the other three start at 1 mm/hour.
1 – 15mm/hour
Between 0 and 1 and between 15 and 20 it depends on the lab, because each sets its limits on its own method and population. Above 20 every lab calls it abnormal.
every lab calls 1 – 15 mm/hour normal. Between 0 and 1 and between 15 and 20 it depends on the lab.
Every age, per lab
| Laboratory | Group | Reference range |
|---|---|---|
| Unilabs(Saltro, Medlon, SHO, Atalmedial)2026 | Men up to 50 yrs | 1–10 mm/hour |
| Men from 50 yrs | 1–15 mm/hour | |
| Women up to 50 yrs | 1–15 mm/hour | |
| Women from 50 yrs | 1–25 mm/hour | |
| Star-shl2026 | Men 10 to 50 yrs | 1–15 mm/hour |
| Women 10 to 50 yrs | 1–20 mm/hour | |
| Men from 50 yrs | 1–20 mm/hour | |
| Women from 50 yrs | 1–30 mm/hour | |
| Certe2026 | Men 10 to 50 yrs | < 15 mm/hour |
| Men from 50 yrs | < 20 mm/hour | |
| Women 10 to 50 yrs | < 20 mm/hour | |
| Women from 50 yrs | < 30 mm/hour | |
| Clinical Diagnostics2026 | Men | 1–15 mm/hour |
| Women | 1–20 mm/hour |
Each band as the lab publishes it, retrieved in 2026, unless marked otherwise.
ESR (sedimentation rate) high or low: what it means
A low sedimentation rate is healthy, and there is no lower limit that means anything. A value at the bottom of the scale means there has been no inflammation of note in the past weeks and that the proteins in your blood are normal. That is the outcome you want. A high sedimentation rate means there is more sticky protein in your blood, and the question is why. In order of how often it occurs: an inflammation or infection that has been running a while, from an inflamed joint to pneumonia or an inflammation in the gut; anaemia, in which fewer cells sink faster; a pregnancy, in which the sedimentation rate naturally rises; and your age, because over fifty the band sits higher for everyone and highest in a woman. A sedimentation rate above a hundred is a different story: it fits a severe infection, an inflammation of the blood vessels, a proliferation of antibody cells or a malignancy, and it should be investigated the same week, even without clear symptoms. What you do about it: nothing to the sedimentation rate itself, but to the reason. With an infection or inflammation it falls by itself in the weeks after recovery, more slowly than CRP, so do not measure again too early. With anaemia it falls along once your iron store is filled. With an inflammation that does not stop, in the joints, the gut or the gums, treating that is the lever, and the smouldering inflammation of belly fat and smoking lifts it slightly, as with CRP. A slightly raised value without symptoms and with a normal CRP you may usually leave alone in a woman over fifty. Always read the sedimentation rate beside CRP, because the two move on a different timescale and the difference between the two is a clue in itself, beside haemoglobin, because anaemia lifts it without inflammation, and beside your age and sex, which determine which band applies to you.
What raises it
There is more sticky protein in your blood, and the question is whether that is inflammation or something else.
| Cause | How often |
|---|---|
| InflammationYour liver makes fibrinogen and your immune system antibodies once an inflammation has run a few days; an inflamed joint, a bowel inflammation or an inflammation of the blood vessels lift it highest | Often |
| InfectionPneumonia, an abscess or an insidious infection; the sedimentation rate rises days after the CRP and stays raised for weeks after recovery | Often |
| AnaemiaFewer red cells sink faster, even without inflammation; a filled iron store brings the value back | Sometimes |
| PregnancyThe proteins in the blood change and the sedimentation rate naturally rises, to far above the band; after the birth it falls again | Sometimes |
| Your ageOver fifty the band sits higher for everyone and highest in a woman; a slightly raised value without symptoms is then usually just age | Sometimes |
| MalignancyA proliferation of antibody cells in the bone marrow lets the sedimentation rate rise to far above a hundred while CRP can be normal; rare, and never on the basis of the sedimentation rate alone | Rare |
How does an ESR (sedimentation rate) blood test work?
- Referral
- Not needed. You can have the sedimentation rate measured yourself, though in a healthy body CRP usually says enough; the sedimentation rate adds something with symptoms that have lasted weeks.
- Fasting
- Not needed; the sedimentation rate does not respond to food or to the time of day.
- When
- Not in the weeks after an infection if you want to know your usual level, because the sedimentation rate stays raised for weeks after recovery. If you want to see whether an inflammation is dying down, measure a few weeks apart.
- The draw
- One tube of blood from a vein in your arm, which stands upright for an hour while the lab measures how far the red cells sink. CRP and a blood count come from the same draw.
- Repeating
- With a raised value after four to six weeks, because the sedimentation rate falls slowly. In a healthy body it need not be more often than with your yearly blood test.
- Where to draw
- You can draw at 250+ locations near you, no referral needed. See the locations
Frequently asked questions
What is the sedimentation rate?
A measurement of how fast your red blood cells sink to the bottom of a tube in an hour, in millimetres per hour. With inflammation your liver makes proteins, especially fibrinogen, and your immune system antibodies, which make the cells stick together; clumps sink faster than single cells. It is an indirect measurement of how much sticky protein is circulating in your blood, and with that a slow but broad gauge of inflammation.
What is a normal sedimentation rate?
That depends on your sex and your age. Where the four labs overlap, the sedimentation rate in a man up to age 50 runs from 1 to 10 mm/hour and from age 50 from 1 to 15 mm/hour; in a woman it runs up to age 50 from 1 to 15 mm/hour and from age 50 from 1 to 20 mm/hour. A low value is healthy at every age, and over fifty the band sits higher for everyone because the proteins in the blood change.
What does a high sedimentation rate mean?
That there is more sticky protein in your blood. Usually that is an inflammation or infection that has been running a few days, and then the value stays raised for weeks after recovery. Without inflammation, anaemia, a pregnancy and your age lift it. A value above a hundred fits a severe infection, an inflammation of the blood vessels, a proliferation of antibody cells or a malignancy, and that is investigated the same week.
What does a low sedimentation rate mean?
Nothing special, and that is good news. There is no lower limit that points to a deficiency or a condition; three of the four labs start their band at 1 mm/hour and Certe prints only an upper bound. A low value says there has been no inflammation of note in the past weeks and that the proteins in your blood are normal. Low is the state you want for the sedimentation rate.
Why does a woman get a wider band than a man?
Because women naturally have a slightly lower haemoglobin and different protein ratios in the blood, which makes the cells sink somewhat faster. All four labs make that distinction: below fifty the shared band stops at 10 mm/hour for a man and 15 mm/hour for a woman, and above age 50 at 15 and 20 mm/hour. A pregnancy lifts the value further still, and that is not inflammation.
What is the difference between the sedimentation rate and CRP?
The pace. CRP rises within hours and falls within days, and tells what is happening now. The sedimentation rate only rises days after the start of an inflammation, because fibrinogen and antibodies come and go slowly, and stays raised for weeks after recovery; it tells what has happened in the past weeks. A high sedimentation rate beside an almost normal CRP points to something that has been smouldering a while, and that difference is a clue in itself.
How do I bring my sedimentation rate down?
By removing the reason; there is nothing to do to the measurement itself. After an infection or inflammation it falls by itself, more slowly than CRP, so do not measure again too early. With anaemia it falls along once your iron store is filled. With an inflammation that does not stop, in the joints, the gut or the gums, treating that is the lever. A slightly raised value without symptoms and with a normal CRP is, in a woman over fifty, usually just age.
When is a high sedimentation rate investigated?
When it goes above a hundred, or when it stays raised without explanation beside symptoms that have lasted weeks: tiredness, weight loss, painful joints, headache with stiff shoulders in older people, or bone pain. Then haemoglobin, kidney function and the proteins in the blood are looked at, because a proliferation of antibody cells lifts the sedimentation rate while CRP stays normal. A slightly raised value in a healthy body does not need that.
Related biomarkers
Sources
- 1.Unilabs, test catalogue (Dutch): ESR. 2026. bepalingenklapper.nl
- 2.Star-shl, test catalogue (Dutch): ESR. 2026. star-shl.nl
- 3.Certe, test catalogue (Dutch): ESR. 2026. bepalingenwijzer.certe.nl
- 4.Clinical Diagnostics, lab guide (Dutch): ESR. 2026. clinicaldiagnostics.nl
- 5.LESA Laboratory diagnostics (Dutch primary-care laboratory agreement). 2026. richtlijnen.nhg.org
Educational information only, not medical advice. Consult a healthcare professional for clinical decisions.
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