Why am I always tired? 22 medical reasons for feeling tired

Anemia

Anemia can lead to a lack of energy because your body isn’t getting enough oxygen. Anemics have less red blood cells in the body, meaning less oxygen gets transported around the body to keep their organs, muscles and tissues functioning at maximum potential.Anemia can be diagnosed by a doctor, and treatment will depend on the exact cause. For many people the cause is iron deficiency, which can be dealt with by taking supplements or eating foods rich in iron, such as meat or leafy green vegetables.