Summary
The Erythrocyte Sedimentation Rate (ESR) measures how quickly red blood cells settle to the bottom of a tube in one hour. Inflammation causes proteins like fibrinogen to rise, making red cells clump and settle faster. ESR is a simple, long-established marker of inflammation used to detect and monitor infection, autoimmune disease, and certain cancers — and is particularly important in diagnosing polymyalgia rheumatica and temporal arteritis.
ESR rises and falls more slowly than CRP, making the two complementary: CRP responds within hours, while ESR reflects inflammation over days to weeks. ESR can remain elevated for some time after the inflammatory trigger has resolved.
ESR is influenced by many non-inflammatory factors — it rises with age, in women, in pregnancy, with anaemia, and in conditions that increase blood proteins (such as myeloma). This makes it less specific than CRP, but its sensitivity makes it useful as a screening and monitoring test.
ESR is especially valuable in suspected polymyalgia rheumatica and giant cell (temporal) arteritis, where a markedly raised ESR supports the diagnosis. It is also used to monitor disease activity in conditions like rheumatoid arthritis and lupus.
What It Is
The ESR is measured by the Westergren method: anticoagulated blood is placed in a vertical tube and the distance red cells fall in one hour is recorded in mm/hr. In inflammation, acute phase proteins — particularly fibrinogen — coat red cells, reducing their negative surface charge and promoting rouleaux formation (stacking), which makes them settle faster.
ESR is a non-specific marker influenced by red cell factors (anaemia raises it; polycythaemia lowers it) and plasma protein factors (fibrinogen and immunoglobulins raise it). It changes more slowly than CRP, rising over 24–48 hours and falling over days to weeks.
Normal ranges are age- and sex-dependent. A commonly used rule of thumb: upper limit ≈ age ÷ 2 in men, and (age + 10) ÷ 2 in women. Very high ESR (> 100 mm/hr) suggests serious infection, autoimmune disease, or malignancy (especially myeloma).
Functions
Inflammation detection
A simple, sensitive marker that rises in infection, autoimmune disease, and inflammation of many causes.
Polymyalgia and arteritis diagnosis
A markedly raised ESR strongly supports polymyalgia rheumatica and giant cell (temporal) arteritis.
Disease activity monitoring
Tracks inflammatory activity over time in conditions such as rheumatoid arthritis and lupus.
Sustained inflammation marker
Reflects inflammation over days to weeks — complementing the faster-responding CRP.
Reference Ranges
Erythrocyte Sedimentation Rate (ESR)
Measured in mm/hr| Status | Range (mm/hr) | What it means |
|---|---|---|
| Normal | < 20 | Normal — no significant inflammation detected (age and sex adjusted). |
| Mildly raised | 20–50 | Mildly elevated — inflammation, infection, anaemia, or age-related rise. |
| Elevated | 50–100 | Significant inflammation — autoimmune disease, infection, or polymyalgia/arteritis. |
| Markedly high | > 100 | Very high — serious infection, autoimmune disease, or malignancy (e.g. myeloma). |
Normal ESR rises with age and is higher in women. Anaemia, pregnancy, and raised plasma proteins increase ESR independently of inflammation. Always interpret alongside CRP and the clinical picture.
Symptoms of Imbalance
ESR itself causes no symptoms; an elevated result reflects an underlying inflammatory, infectious, or other process.
- Low ESR is not clinically significant
- Very low ESR may occur with polycythaemia or some red cell disorders
- Symptoms of the underlying condition (infection, arthritis, etc.)
- Shoulder and hip girdle pain and stiffness (polymyalgia rheumatica)
- Headache, scalp tenderness, jaw pain (temporal arteritis)
- Fatigue and malaise
- Fever, night sweats, weight loss (with serious causes)
Causes of Imbalance
- Polycythaemia (high red cell count lowers ESR)
- Sickle cell disease and other red cell shape abnormalities
- Very high white cell counts
- Low ESR is generally of little clinical concern
- Infections (acute and chronic)
- Autoimmune and inflammatory diseases (rheumatoid arthritis, lupus, vasculitis)
- Polymyalgia rheumatica and giant cell arteritis
- Anaemia
- Malignancy, especially multiple myeloma and lymphoma
- Chronic kidney disease
- Pregnancy and increasing age (physiological)
FAQs
Both are markers of inflammation, but they behave differently. CRP is produced rapidly by the liver and rises within hours of inflammation, falling quickly when it resolves. ESR changes more slowly, rising over a day or two and remaining elevated for days to weeks. CRP is more specific; ESR is influenced by age, sex, anaemia, and blood proteins. Measured together, they give a fuller picture of both acute and sustained inflammation.
ESR increases naturally with age, partly due to gradual rises in fibrinogen and other plasma proteins, and is also higher in women. Because of this, the ‘normal’ upper limit is age- and sex-adjusted — a common rule of thumb is age ÷ 2 for men, and (age + 10) ÷ 2 for women. A mildly raised ESR in an older person may therefore be normal for their age.
A very high ESR (over 100 mm/hr) points to significant underlying disease — most often serious infection, active autoimmune disease, or malignancy, particularly multiple myeloma or lymphoma. It warrants careful investigation. In an older adult with a new headache, scalp tenderness, or jaw pain, a very high ESR raises concern for giant cell arteritis, which needs urgent assessment to protect vision.
Yes. ESR depends partly on the number and behaviour of red blood cells. Anaemia (a low red cell count) raises ESR independently of any inflammation, because fewer red cells settle faster. Conversely, a high red cell count (polycythaemia) lowers ESR. This is one reason ESR is always interpreted alongside a full blood count and, ideally, CRP.
References
- Brigden ML. Clinical utility of the erythrocyte sedimentation rate. Am Fam Physician. 1999;60(5):1443–1450. View source
- Harrison M. Erythrocyte sedimentation rate and C-reactive protein. Aust Prescr. 2015;38(3):93–94. View source
- Dasgupta B, et al. BSR and BHPR guidelines for the management of giant cell arteritis. Rheumatology. 2010;49(8):1594–1597. View source