homegrown health literacy part 1.1: WTF is ESR?
hello and welcome to the first post in my series about knowing when your doctors are full of shit! part 1 will be about interpreting bloodwork results.
disclaimer: i’m Just Some Guy
ESR is a blood test that measures inflammation. it’s a general test, so it can’t say what chronic or acute condition is causing the inflammation, just that it’s there.
ESR stands for erythrocyte sedimentation rate. it may also be listed on bloodwork reports as a Westergren test, and may be referred to as “sed rate.” the test essentially measures how quickly your red blood cells settle to the bottom of a container; sinking faster means you’re more inflamed.
normal results for ESR are classified by “sex.” current medical science is not transparent about what factors obscured under the label of “sex” actually affect test results – hormones? organs? body size? social factors? – so it’s unclear what variables are at play here. most likely, the average higher results in people classified as “female” are due to a combination of body size, hormones, and menstruation. however, many autoimmune conditions that cause inflammation are more common in people considered “female” by mainstream medicine, so i maintain some skepticism about whether the people considered healthy when constructing these averages actually were.
personally, as a tall, fat person who takes testosterone and does not menstruate, i compare my results to the “male” category. use your best judgement when evaluating your own results.
results considered “normal” for an ESR would be as follows, measured in mm/hr:
children before puberty: less than 10
“females” age puberty through 50: less than 20
“males” age puberty through 50: less than 15
“females” over 50: less than 30
“males” over 50: less than 20
results on the high end of normal would often merit redoing the test a few weeks or months later, or conducting other tests for inflammation such as CRP. as a point of reference, my ESR was 40 when it was used to help diagnose me with ankylosing spondylitis at age 22.
ESR increases with age, so a thirteen-year-old cisgender perisex girl who’s going through puberty would be expected to have a lower ESR than a 49-year-old cisgender perisex woman, even though their results are classified within the same category. it is also common for ESR to be elevated during pregnancy.
keep in mind:
averages are just that; ideally, comparing results from the same person over time gives the best clinical picture.
similarly, age 50 is not a magic number; an ESR of 30 in a cisgender perisex woman at age 49 might not indicate an underlying condition, and an ESR of 30 in a different cisgender perisex woman at age 51 might.
no one blood test can rule most conditions in or out; a negative/normal ESR does not mean you don’t have an autoimmune disease.
