Low blood pressure and lack of energy and fatigue are commonly caused by malnutrition, hypothyroidism, blood volume insufficiency and other reasons. 1. Malnutrition: Due to insufficient supply of nutrients to meet the body’s normal needs, hypoglycemia and anemia can easily occur, and the symptoms of low blood pressure and lack of energy can also occur. 2. Hypothyroidism: due to insufficient secretion of the thyroid gland, resulting in generalized metabolic depression, in addition to low blood pressure and lack of energy and fatigue may also have symptoms such as depressed mood. 3. Insufficient blood volume: Loss of blood due to trauma or loss of body fluids due to diarrhea can cause insufficient blood volume, resulting in the above symptoms, and need to replenish blood volume in a timely manner. If you have low blood pressure, you should pay attention to it and go to the hospital as soon as possible to do the relevant examination and active treatment to avoid damage to important organs due to insufficient perfusion.