Ask a student to name diseases that affect the human body and they can develop a pretty lengthy list of infectious and chronic conditions. Large portions of popular media and news are dedicated to showcasing any number of ailments. Given the widespread coverage of recent epidemics like Ebola and listeria, many students are able to explain how someone can catch a disease. Many students can also start to explain the underlying causes behind some non-communicable diseases like Alzheimer’s and diabetes. It is easy to understand how foreign bodies like bacteria, viruses, and parasites can cause problems in our bodies. These particles do not belong and, as such, can cause devastating effects to our tissues. It is the formation of non-communicable diseases—diseases that form when our bodies fail or are unable to maintain themselves—that are more difficult to understand.
However, what is the actual process behind ‘getting sick’? Is it something that just happens to us or are there underlying reasons that lead to the development of disease? More importantly, what stops us from getting sick in the first place… or keeps illness at bay until the end stages of our life?
Our bodies are at attention, keeping an eye out for potential trouble makers whether they come from the outside like allergies and bacteria or from within the cells of our bodies like cancer. Several methods of surveillance work together to keep our bodies in homeostasis—to keep our body systems operating and healthy.
But what happens when those surveillance systems fail?