Causes of shortness of breath, weakness and lack of appetite include fatigue, coronary heart disease, anemia, etc. According to the cause of the disease, you can take more rest, take nitroglycerin, iron supplements and other treatments. 1. Overwork: lack of sleep, overwork and other symptoms such as shortness of breath, fatigue, lack of appetite, etc., at this time you need to take a good rest in order to alleviate the symptoms. 2. Coronary heart disease: Coronary heart disease is caused by the narrowing of coronary arteries, resulting in insufficient blood supply to the heart, shortness of breath, fatigue, lack of appetite and other symptoms, which can be relieved by taking nitroglycerin. Adverse effects of nitroglycerin include headache, postural hypotension, etc. It is contraindicated in patients with severe anemia, increased intracranial pressure, early myocardial infarction (when there is severe hypotension and tachycardia), and those who are allergic to this drug. 3. Severe anemia: when severe anemia, shortness of breath, fatigue, lack of appetite and other symptoms, if iron deficiency anemia, iron supplements such as ferrous sulfate to alleviate the symptoms. Adverse effects of ferrous sulfate include epigastric pain, constipation, black stools, etc. Use with caution in patients with hepatitis, enteritis, pancreatitis, etc., and do not take it at the same time as strong tea. The causes of shortness of breath and lack of appetite are not limited to this, if the above symptoms, it is recommended to go to the hospital in a timely manner, early formal treatment, the above medication should be used under the guidance of a doctor.