Abstract Diabetes mellitus and thyroid problems frequently coexist and have a tight connection. Studies have indicated that persons with diabetes mellitus are more likely to have thyroid issues than vice versa. With its effects on pancreatic beta-cell formation and glucose metabolism in a number of organs, including the liver, gastrointestinal tract, pancreas, adipose tissue, skeletal muscles, and the central nervous system, thyroid hormone influences glucose homeostasis. The impact of thyroid hormone on glucose homeostasis is covered in this review. We also go through recommendations for thyroid function testing in each problem, as well as the connection between thyroid dysfunction and diabetes mellitus, including type 1, type 2, and gestational diabetes. The following are the results of a survey conducted by the American Psychological Association.