Diabetes mellitus is a group of metabolic diseases characterized by elevated blood glucose levels (hyperglycemia) which could be caused by flaws in the secretion of insulin, its action, or both. An estimated one in ten people in the world were living with diabetes in 2021. The two major types of diabetes are type I and type II. Insulin should be started on the day of diagnosis for patients with type I diabetes. Insulin regimens should be individualized based on age, general health, lifestyle, diet, hypoglycemia awareness, ability for self-management, general health, adherence, and social and financial aspects. The most successful insulin regimens for managing type I diabetes are those that combine basal and bolus insulin. Such regimens attempt to mimic the pancreas’ normal activity. Type II diabetes treatment regimens and glycemic targets should be individualized. Such treatment regimens should aim to avoid and treat hyperglycemia and reduce the risk of macrovascular and microvascular complications. The choice of the treatment regimen at the diagnosis of type II should depend on the difference between the patient’s A1C and their individual target and the presence of symptomatic hyperglycemia and/or metabolic decompensation. If not contraindicated, metformin is considered the first line of treatment in patients with type II diabetes. The presence of established cardiovascular, renal disease or cardiovascular risk factors should govern the choice of the second-line agent. If the patient has established cardiovascular disease, renal disease or two cardiovascular risk factors in those who are 60 years or older, then we should choose an agent with demonstrated cardiorenal benefits such as GLP-1 receptor agonists and SGLT2 inhibitors. If the patient does not have any of the aforementioned conditions, the choice of the second-line agent should consider the patient’s medical history, social and work factors, their preferences and values, and the agent’s characteristics.