First off, ask yourself this: Do you treat your body right? "With my patients, I talk about the three pillars of health: sleep, diet, and exercise," says Theodore Friedman, MD, PhD. "If yo… See more

It's a disorder that makes it hard for your blood to move oxygen around your body. A common type is called "iron-deficiency" anemia. Iron acts like a train car that transports … See more

Doctors don't know exactly why it makes people so tired. One likely reason is that your body uses lots of energy to deal with your frequent changes in blood sugar levels. Wha… See more

It's a small, butterfly-shaped gland that sits in your neck. It makes a hormone that helps control how you use energy. When your thyroid gland is out of whack, you're out of whack. "Pe… See more