If you have prolonged stress, your white blood cells make more pro-inflammatory proteins. In the short term, this is a defense against infection. But over time this inflammation can cause damage to healthy tissue.
What does all of this mean? In part, it means that a person who strives to be happy by giving to others and living a meaningful life will be healthier than people who are focused on pleasing themselves. Not too surprising is it? But now we have scientific proof that it’s true.