The number of people with diabetes worldwide jumped by more than four times from 108 million to 422 million between 1980 and 2014. About 8.5% of adults globally have the condition. In 2016, an estimated 1.6 million deaths were directly caused by diabetes, making it the seventh leading cause of death that year.

As of 2015, 30.3 million Americans, or just over 9% of the population, were living with diabetes. In 2017, 84 million had prediabetes, or higher than normal blood sugar levels, which will turn into diabetes if left untreated.

This chronic disease affects how the body turns food into energy. The key player in the process is insulin, a hormone released by the pancreas in response to rising glucose levels in the blood.

There are three types of diabetes. People with Type 1 diabetes, about 5% of diabetics, make very little or no insulin. They must take insulin every day to live. People with Type 2 diabetes don’t use insulin well. Their body is not capable of regulating blood sugar levels. The third type, gestational diabetes, develops in pregnant women and normally goes away after childbirth.

Some of the most severe diabetes complications include ketoacidosis, which can be fatal, kidney disease, amputation, and blindness.

To compile a list of the 10 biggest warning signs of diabetes, 24/7 Wall St. reviewed multiple studies and reports by independent health organizations, such as the American Diabetes Association, JDRF, a leading Type 1 diabetes research group, the American Academy of Dermatology, the National Institute of Diabetes and Digestive and Kidney Diseases, and the National Institutes of Health.

Click here to read about the 10 warning signs you may have diabetes.