People like myself who love spicy food may love it in part because it releases endorphins in the body. When capsaicin, the element of chili peppers that cause the “spicy” sensation, comes into contact with the tongue, the body is tricked into believing that it is in pain and releases the pain-relieving endorphins.
This explains why, like anything that releases endorphins, spicy food can become somewhat addictive. People may crave it and build tolerance levels so that, say, the 30,000 HU cayenne that once seemed very spicy starts to seem quite mild.
There’s no reason to worry about this spicy food addiction, though. You’ll never have physical withdrawal symptoms, destroy your life because of them, or need chili peppers just to feel good. It’s a benign addiction and given the many health benefits of spicy food, a healthy one.