Myocardial infarction is a serious health problem affecting populations worldwide. Proper and prompt diagnosis and management is critical to achieving good prognosis and avoiding or reducing morbidity and mortality. It is essential for clinicians to be aware of the risks, diagnosis and treatment. In this review we aim to update and discuss knowledge of myocardial infarction with respect to risk factors, pathophysiology, types or classification, clinical manifestations, diagnosis and treatment in a concise and simplified manner in order to define a simple comprehensive guide for clinicians. The available literature has been searched, reviewed, studied, analyzed, written in a simple understanding method, discussed and concluded. For prophylaxis, it has been found that moderate muscular exercise, regular consumption of fresh vegetables and fruits, avoidance of smoking and stress, and low consumption of fat are associated with reduced risk of coronary heart disease in populations of all age groups worldwide. The diagnosis of myocardial infarction is based primarily on evaluations of clinical features, typical abnormalities in ST-segment and T wave of ECG findings and rise in cardiac enzymes or biomarkers such as plasma troponin. At the same time, the key to treatment is reperfusion of the myocardium and restoration of coronary blood flow.