There are four main types of diabetes mellitus:

• Type 1 diabetes mellitus

• Type 2 diabetes mellitus

• Diabetes mellitus associated with other causes

• Gestational diabetes mellitus

Each has its own physiological causes and, as such, different treatment strategies. It is important to recognize that, even in each group, there is a considerable degree of variability in clinical presentation. For example, previously it was believed that only children and young adults could develop type 1 diabetes mellitus, and currently it is estimated that approximately 50% of newly diagnosed cases of type 1 diabetes occur in adults. The difference is that, in adults, type 1 diabetes usually doesn't cause the same sudden and severe presentation that occurs in children.

There is a current of thought according to which people with diabetes usually combine several mechanisms of high blood sugar. Depending on each individual "cocktail" of genes, each person with diabetes will have their own clinical presentation and evolution over time. So, for example, if a person has a very high susceptibility for autoimmunity, type 1 diabetes may begin early in childhood with rapid loss of the insulin producing capacity. Or, if a person has a specific, genetic form, of diabetes, and also a high risk for insulin resistance, severe diabetes may emerge which would otherwise be mild.

You can find more information about each type of diabetes - just follow the links above.

Diabetes mellitus

1. Introduction and diagnostic criteria

2. Types of diabetes

References

Redondo MJ, Hagopian WA, Oram R, Steck AK, Vehik K, Weedon M, Balasubramanyam A, Dabelea D. The clinical consequences of heterogeneity within and between different diabetes types. Diabetologia. 2020 Oct;63(10):2040-2048. doi: 10.1007/s00125-020-05211-7. Epub 2020 Sep 7. PMID: 32894314; PMCID: PMC8498993.

Pallete model and Threshold hypothesis for the emergence of high blood sugar (See reference below)