It is a common phenomenon that the body is tired and drowsy when menstruation comes. It is considered that the body will show a lack of blood due to the loss of blood during menstruation. If the menstrual flow is usually very heavy, you should see a doctor for an ultrasound examination of the uterus to be alert to the possibility of fibroids and other diseases. If your body is anemic, you should pay attention to finding the specific cause of the anemia and then give the appropriate treatment. When your body’s immune function decreases during menstruation, you should take more rest to ensure adequate sleep and nutrition and avoid strenuous sports.