Always exhausted? It may not be stress or stretching yourself too thin. Find out the real medical reason you're exhausted. Dr. Oz set up his own lab and uncovered the 4 secret reasons you're over-tired.

Click here for Part 1 of Dr. Oz's Exhaustion Lab.

Click here for Part 2 of Dr. Oz's Exhaustion Lab.

You've heard of red wine and white wine but have you ever heard of blue wine? This blue version of wine is given a taste test to see how it compares to the classics.