Yesterday, I had a check-up with a new doctor, and got some blood work done. My white blood cell (WBC) count was 3.7 k / uL, which is just below the normal range of 4.0 to 11.0. I checked past results that were taken with a different doctor's office, and it turns out that since 2019 my WBC count has fluctuated between 3.4 and 5.0 (with one blip at 6.0). This wasn't flagged as abnormal, because that office used a lower reference range.

My doctor described the result as "just a little bit on the low side but overall nothing significant concerning at this time" has told me to re-test in a week or so "to make sure it is not a continuing trend", at which point I assume my WBC count will be hanging around 4.0 or so.

For reference: I am a 29 year old man, height 5'8", weight 168 lbs, BMI 25.0, vegan diet. I haven't noticed serious health problems, but have not been super energetic at work (which I have chalked up to the difficulty of the job). Late last year I tested at low ferritin levels, which I then brought back up into the normal range by supplementation.

By "a medical practitioner" I basically mean the medical system, if someone who happens to be a doctor tells me something socially that doesn't count. "Medical treatment" means medicine or surgery, not "exercise more" or "eat some vegetables".

Happy to answer questions in the comments.