21/05/2026
Behind your sternum sits a small organ called the thymus. It's where your body trains new immune cells to recognize and fight threats. It starts shrinking after puberty, and by your 40s, much of it has been replaced by fatty tissue. The production line slows down — and your body starts relying on older immune cells trained for threats you've already faced. Good at fighting what it knows. Slower to respond to what it doesn't.
This gradual decline has a name: immunosenescence. It doesn't just mean getting sick more often. It means weaker detection of infections and cancer. It means immune responses that misfire against your own tissues. And it means chronic, low-grade inflammation — even with nothing to fight.
Researchers call that inflammation "inflammaging." Not visible. Not acute. Just a persistent background signal that quietly accelerates tissue breakdown across joints, blood vessels, and the brain. The damaged cells that should be cleared start accumulating, releasing their own inflammatory signals, pushing the immune system further behind.
Aging doesn't start with a symptom. It starts with a system that quietly stops keeping up.
