Why Am I so tired and feel exhausted. When you looking on the bench press, you feel your energy is disappeared, gone nowhere. Next article feature by webmd, Why fatigue came into your life. Anemia "If you are in your reproductive years, and particularly if you experience heavy menstrual cycles, have fibroid tumors or uterine polyps, or if you've recently given birth, the blood loss may have caused you to develop anemia -- a leading cause of fatigue in women," says Amaru. Problems occur, she says, when the bleeding leads to a deficiency of hemoglobin, the iron-rich protein in red blood cells that carries oxygen from the lungs to other parts of your body. When your tissues and organs don't get enough oxygen, she says, the result is fatigue. Other causes of anemia include internal bleeding, or a deficiency of iron, folic acid, or vitamin B12. Anemia may also be caused by chronic diseases like kidney disease, for example. Symptoms can include dizziness, feeling cold, and ...