Infectious diseases are caused by harmful microorganisms such as bacteria, viruses, fungi, and parasites. These diseases can spread from person to person, through contaminated food or water, insect bites, or exposure to infected surfaces. While some infections are mild and self-limiting, others can be severe or even life-threatening if not treated promptly. When this process is disrupted, glucose accumulates in the bloodstream, resulting in high blood sugar levels (hyperglycemia). Over time, uncontrolled diabetes can lead to severe health complications, affecting multiple vital organs.