What Those Lab Tests Actually Mean (And Why Your Doctor Tracks Them)

“What does this mean?” she’d ask, pointing to her bilirubin level.

My mother had blood drawn every 4 months for the last decade of her life. She’d come home with a printout showing numbers, reference ranges, and little flags marked “H” or “L” for high or low.

“What does this mean?” she’d ask, pointing to her bilirubin level.

“Your bilirubin is probably fine, Mom.”

“But it says high right here.”

“It’s barely above range. The doctor’s watching it. That’s why we test every 4 months.”

She wasn’t satisfied with that answer. She wanted to understand what those numbers meant and why her doctor kept ordering the same tests. After forty years as a radiologist, I understood the system. But my mother — and most seniors I know — felt like they were being poked, prodded, and tested without anyone explaining the why behind it all.

If you’re getting regular blood work and staring at results you don’t understand, you’re not alone. Let me walk you through the five most common lab tests your doctor orders and what they’re actually tracking.