Responding to "How are you?"

In some countries (the United States, among others), the question "How are you?" is often asked as an alternative greeting. In these countries, the expected answer is usually "I'm fine/good, thanks. How are you?" Answering honestly, especially in any detail, may cause the other person to respond with surprise or confusion.

In other countries, this question may be a legitimate (albeit likely brief) inquiry into your health.

A similar question in the UK is "All right?" or "You all right?" Sometimes it basically just means "Hello" - I think the expected responses include something along the lines of "Hi, yes, you?" or a smile/nod combo or even repeating "All right?" back to them. You definitely aren't expected to describe your current state of being accurately or in detail.