Weakness and lack of energy may be caused by poor rest, anemia, hypothyroidism and other reasons. 1. Irregular work and rest: If you don’t have a regular work and rest routine and often stay up late, you may experience weakness and lack of energy. It is recommended that you pay more attention to rest and don’t overexert yourself, which can alleviate the symptoms to a certain extent. 2. Anemia: If there is anemia, there may be weakness, no spirit, this situation is recommended to improve the blood routine examination, by taking iron, folic acid, vitamin B12 and other medications, if necessary, also need to carry out blood transfusion. 3. Hypothyroidism: If the thyroid function is low, there may be weakness, no spirit, this situation is recommended to improve the thyroid function test, if necessary, need to take levothyroxine sodium tablets and other drugs, it is recommended to follow the doctor’s instructions to use drugs. If the weakness and lack of energy lasts for a long time, it is recommended to consult a doctor in time, improve the examination and treat the symptoms.