The side effects of long-term use of Metoprolol Succinate Extended-Release Tablets on the body are mainly in the form of headache, dizziness, fatigue, tachycardia, coldness in the extremities as well as nausea, vomiting, abdominal pain and diarrhea. The side effects of Metoprolol succinate extended-release tablets are mainly manifested in the following aspects: 1. Digestive system: nausea, vomiting, abdominal pain, diarrhea and constipation. 2. Nervous system: headache, dizziness, fatigue, sleep disorders, sensory abnormalities and so on. 3. Circulatory system: chest pain, tachycardia, cold limbs and heart failure. 4. Skin: Rash, itching, and photosensitivity. 5. Respiratory system: manifested as shortness of breath, and may even induce asthma. 6. Other aspects: weight gain, excessive sweating, hair loss, as well as altered sense of taste may occur. The drug should be used with caution in pregnant women, lactating women, hepatic insufficiency, and is contraindicated in people with II and III atrioventricular block, and those with severe bradycardia. The drug should be applied under medical supervision.