What’s in Blood

Time To Read

2–3 minutes

Date Last Modified

14

CHART CLUE

Three of Stina’s blood findings keep being read alone: a mild anemia that no amount of iron will fix, a platelet count that climbs during every flare, and a serum CRP that sits sky-high year after year. Filed separately, they look like odd, harmless labs. Read together, they are one sustained acute-phase response and the liver is quietly seeding something dangerous.

A single spun tube of Stina’s blood tells most of the story at a glance. The straw-colored plasma rises to the top, a thin pale band of white cells and platelets — the buffy coat — sits in the middle, and the dense red cells pack the bottom. The proportions matter: her packed red-cell fraction runs a little low (her anemia), while during flares that middle band thickens with extra platelets and neutrophils. The tube is a snapshot of her whole case.

Each fraction has a job. Plasma — about 55% of blood — is mostly water carrying proteins (albumin, clotting factors, antibodies), nutrients, hormones, and wastes. The formed elements below it are red cells that carry oxygen, white cells that defend, and platelets that begin repair. Two quick measures name what the tube shows: the hematocrit is the percentage of blood volume that is packed red cells, and the buffy coat is that thin white-cell-and-platelet layer between plasma and red cells. Building this inventory first matters because every clue in Stina’s chart — low hematocrit, flare-time platelets, acute-phase proteins in the plasma — is just one of these fractions behaving abnormally.

The red cells at the bottom of the tube don’t last forever — they’re born, they work for months, and they’re retired. Follow one through its life, because that cycle is exactly where Stina’s anemia begins.

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The Anemia That Won’t Quit

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Making and Recycling Red Cells

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