09/03/2026
Your blood cells have to bend just to keep you alive.
A resting red blood cell is wider than some of the smallest capillaries in your body. To get through, its flexible membrane changes shape, allowing the cell to squeeze along the vessel in single file.
This is not accidental. Passing so close to the capillary wall helps red blood cells release oxygen exactly where your tissues need it.
These cells repeat this microscopic squeeze throughout their journey bending, recovering their shape and continuing forward without normally breaking.
Your bloodstream is far more flexible than it looks.