Hi. Welcome to HCM. Metoprolol belongs to group of drugs called beta-blocker that affects the heart and circulation. It used to treat angina (chest pain) and hypertension (high blood pressure). It is also used to treat or prevent heart attack. It is not prescibed for patients having asthma, chronic obstructive pulmonary disease, Diabetes, liver disease, heart failure ,thyroid disorder. So if u r suffering any of the above and taking metoprolol u have to consult your doctor. Common metoprolol side effects may include dizziness, tired feeling, confusion, memory problems, nightmares, trouble sleeping, diarrhea. If u experience light head feeling, shortness of breath and cold feeling in your hands and feet please call your doctor immediately and remember your doctor has prescribed u after weighing the risks and benefits. U should be aware of these side effects and no need to get scared. Regards