Type 2 diabetes is a metabolic disorder characterized by high blood sugar levels caused by insulin resistance (when the body's cells do not respond appropriately to insulin) and/or decreased insulin production by the pancreas. It is not fully understood what causes type 2 diabetes, but it is believed to be a complex interaction between genetic, environmental, and lifestyle factors. 

Type 2 diabetes may manifest with symptoms including increased thirst and urination, blurred vision, fatigue, and sluggish wound healing. However, many individuals with type 2 diabetes may exhibit no symptoms, especially in the disease's early stages. 

Long-term complications of poorly controlled type 2 diabetes include cardiovascular disease, kidney damage, nerve damage, eye damage, and an increased infection risk. In addition, people with type 2 diabetes are more likely to develop other health conditions, such as high blood pressure and high cholesterol.

Diagnosis of Diabetes: 

• A1C ≥ 6.5%. The A1C test measures the average level of glucose in a person's blood over the past two to three months. 

• OR 126 mg/dL (7.0 mmol/L) FPG (fasting plasma glucose). Fasting involves abstaining from food and drink, with the exception of water, for at least eight hours prior to a test. 

• OR 2-hour plasma glucose 200 mg/dL (11.1 mmol/L) during an oral glucose tolerance test (OGTT). Two hours after ingesting a special glucose solution, blood glucose levels are measured during the OGTT. Notably, a diabetes diagnosis must be confirmed by repeating the test on a separate day, unless there are clear symptoms of hyperglycemia or a random plasma glucose test 200 mg/dL (11.1 mmol/L) with symptoms. 

Diagnostic Criteria for Prediabetes:

•  A1C ranging from 5.7% to 6.4%. OR Plasma glucose at fasting (FPG) between 100 and 125 mg/dL (5.6 and 6.9 mmol/L). 

• OR a 2-hour plasma glucose between 140-199 mg/dL (7.9-11.0 mmol/L) during an oral glucose tolerance test (OGTT). 

People with prediabetes are more likely to develop type 2 diabetes and other health conditions, such as cardiovascular disease. People with prediabetes can prevent or delay the onset of type 2 diabetes through changes in lifestyle, such as healthy eating and physical activity. Working with a healthcare provider to obtain an accurate diagnosis and an individualized treatment plan for diabetes or prediabetes is essential. 

Symptoms, blood tests (such as fasting blood sugar levels and hemoglobin A1c), and a glucose tolerance test are typically used to diagnose type 2 diabetes. In some instances, a physician may also order a test to measure insulin levels or to rule out other possible causes of symptoms. 

Treatment options for type 2 diabetes generally include lifestyle modifications and medication. Changes in lifestyle may include dietary modifications, regular exercise, and weight control. There are oral medications (such as metformin) and injectable medications for type 2 diabetes (such as insulin and glucagon-like peptide-1 receptor agonists, or GLP-1 agonists). Several classes of oral medications, including metformin, sulfonylureas, meglitinides, thiazolidinediones, and dipeptidyl peptidase-4 (DPP-4) inhibitors, can be used to treat type 2 diabetes. These medications lower blood sugar levels and increase insulin sensitivity through various mechanisms. 

Insulin Therapy Insulin therapy may be required for individuals with type 2 diabetes who are unable to adequately control their blood sugar levels through lifestyle changes and oral medications. Insulin can be administered via injection or insulin pump. 

Modern GLP-1 and SGLT Therapies: Newer medications for the treatment of type 2 diabetes include GLP-1 receptor agonists and sodium-glucose cotransporter 2 (SGLT2) inhibitors. These medications function by increasing insulin sensitivity and decreasing liver glucose production. They may also have additional benefits, such as weight loss and a reduction in blood pressure. 

Endocrinologist Follow-Up Individuals with type 2 diabetes should receive ongoing care from a healthcare provider, which may include an endocrinologist, a specialist in the treatment of hormonal disorders such as diabetes. Regular follow-up visits can aid in ensuring that blood sugar levels are well managed and that any potential complications are identified and treated promptly. Healthcare providers may also provide education and support to help type 2 diabetes patients effectively manage their condition.