Research from Stanford University has shown that complaining shrinks the hippocampus—an area of the brain that’s critical to problem solving and intelligent thought. Damage to the hippocampus is scary, especially when you consider that it’s one of the primary brain areas destroyed by Alzheimer’s.

All the extra cortisol released by frequent complaining impairs your immune system and makes you more susceptible to high cholesterol, diabetes, heart disease, and obesity. It even makes the brain more vulnerable to strokes.

Taking time to contemplate what you’re grateful for isn’t merely the right thing to do; it reduces the stress hormone cortisol by 23%.