Erythrocyte sedimentation rate tests (or ESR tests for short) are a non-specific measure of inflammation. The laboratory test, invented by Edmund Faustyn Biernaki, has been in use since the late 1800’s.
ESR tests are useful because they are inexpensive, non-invasive, and require little preparation. They only require a small sample of blood.
ESR is used to help monitor chronic symptoms that could hint at deeper issues including:
- weight loss
- loss of appetite
ESR is used as an early screening tool for lupus. When patients come to the doctor with some of the potential symptoms of lupus, it can confirm that inflammation is occurring within the body.
What Happens During an Erythrocyte Sedimentation Test?
ESR tests measure how fast red blood cells (erythrocytes) settle at the bottom of a blood sample. All this test requires is holding the sample vertically and still for a certain amount of time, and seeing how many blood cells have settled after that time.
Normally, red blood cells settle slowly. However, when there is inflammation in the body, this creates particles called fibrinogens that can pull red blood cells together in clumps. These clumps fall faster than normal, leading to a faster ESR.
The sediment is not measured. Instead, the distance between the clear liquid at the top of the tube (the plasma) and the red blood cells still in solution after one hour.
The normal rates are based on age and gender, and, according to WebMD, the normal rates fall at around:
|Women younger than 50 years old||0 to 20 mm/hour|
|Women older than 50 years old||0 to 30 mm/hour|
|Men younger than 50 years old||0 to 15 mm/hour|
|Men older than 50 years old||0 to 22 mm/hour|
What can affect your test?
Pregnancy, menstruation, and several medications and supplements can interfere with an ESR. The following can increase your ESR (making it look like you have inflammation in the body, even when you don’t):
- Menstruation (having your period)
- Methyldopa (Aldomet)
- Oral contraceptives
- Penicillamine procainamide
- Vitamin A
Medication can also decrease your ERS, masking inflammation. Aspirin, cortisone, and quinine can all impact ESR scores
Laboratory error can also lead to incorrect results if the sample is left to stand for over 3 hours or it is held at an angle during the testing.
What can ESR detect?
ESR tests detect inflammation in the body, making them useful for detecting the presence of many diseases. These diseases include arthritis (including rheumatic arthritis), infection, rheumatic fever, vascular disease, inflammatory bowel disease, heart disease, arteritis (thickened arteries), kidney disease, and certain cancers, polycythemia, sickle cell anemia, leukocytosis (abnormal white blood cells), and autoimmune diseases such as lupus.
Can ESR Diagnose Lupus?
Erythrocyte Sedimentation Rate tests can detect inflammation, but cannot determine the source of inflammation. That is, it can tell you that something is going on in your body, but not what. A high rate can also mean other issues in the body, such as anemia.
Other laboratory tests, such as complete blood counts and CRP protein tests, are needed to determine what the issue is, diagnose it, and find the correct treatment. You can read more about other tests used to diagnose lupus here.
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