Infectious diseases obviously affect us; our personal health, and the personal health of other people. If someone else has an infectious disease then you would probably stay away from such a person. If you had an infectious disease, other people would probably stay away from you. This isn't true for noninfectious diseases where we don't have to worry about infecting or being infected by other people.
I believe the answer is: They both cause your body not to work properly
Depending on the type of disease, both infectious and non infectious diseases could be fatal for your personal health. (example would be AIDs for infectious diseases and heart attack for non infectious)
The main difference between the two is on how the diseases are affecting the people around you.
