Infectious diseases are illnesses caused by pathogenic microorganisms like bacteria, viruses, fungi, or parasites. These diseases can spread directly or indirectly from person to person, through contaminated food or water, insect bites, or airborne transmission. Common examples include influenza, tuberculosis, COVID-19, malaria, and HIV/AIDS.
On the other hand, non-infectious diseases are not caused by infectious agents and are typically not contagious. These conditions often arise due to genetic factors, lifestyle choices, environmental exposures, or a combination of these factors. Non-infectious diseases encompass a broad range of health issues such as cardiovascular diseases (like heart disease and stroke), cancer, diabetes, autoimmune disorders, allergies, mental health disorders, and chronic respiratory conditions like asthma.
While infectious diseases are characterized by the presence and spread of pathogens, non-infectious diseases primarily arise from internal dysfunctions, external factors, or a combination of both. Both types of diseases have significant impacts on individual health, public health, and healthcare systems, albeit through different mechanisms of origin and transmission.