4 Reasons Why Youre Tired

Anemia affects your red blood cells, making them less effective at delivering oxygen throughout your body, Rebecca J. Stoltzfus, PhD, a professor at Cornell University and iron researcher told O.

And if your body isn't getting the oxygen it needs, you're going to feel tired and weak.

Causes of anemia can be heavy menstrual periods, pregnancy, avoidance of red meat, being a vegetarian, or being a serious distance runner.