Fasting insulin 19.9mU/L is not high and is generally not serious.
Insulin is produced by pancreatic islet B cells and is the only hormone in the body that lowers blood glucose. Insulin in the blood will be regulated by blood glucose concentration, and elevated blood glucose can stimulate pancreatic islet B cells to secrete insulin. The normal range of serum fasting insulin is 5-20 mU/L, so insulin 19.9 mU/L is within the normal range.
The test of insulin level can be used to clarify the type of diabetes, and can also assist in the diagnosis of islet cell tumors, liver function abnormalities and other diseases, it is recommended to go to the hospital when there is an abnormal insulin level, and ask a professional doctor to make a judgment.