Diabetes mellitus is a chronic disease where the pancreas cannot produce enough insulin or the cells stop responding to insulin, causing glucose in the blood to not be absorbed by body cells. Common symptoms include frequent urination, lethargy, excessive thirst, and hunger. Diabetes can be caused by diet, genetics, stress, lifestyle, hypertension and other factors. Treatment involves changes in diet, oral medications, and daily insulin injections. There are two main types of diabetes: type 1 typically seen in children and type 2 mostly seen in adults.