Non-infectious diseases are those diseases that are not caused by a pathogen and cannot be shared from one person to another. Diseases caused by these organisms are infectious diseases. There are many kinds of non-infectious diseases.
A non-infectious disease is a disease that may be caused by either the environment, nutritional deficiencies or genetic inheritances. Some examples include; Environmental causes such as skin cancer from radiation (from the Sun), or lack of food (e.g. scurvy from lack of Vitamin C), genetic disorders, or any source other than an infection. They can also be caused by drugs and carcinogens (cancer-causing agents).
Non-infectious diseases cannot be spread from person to person as in infectious disease, but can be passed down genetically in some cases such as hemophilia in the royal blood line.
Historically, infectious diseases were the main cause of death in the world and, indeed, in some developing regions this may still be the case. With the development of antibiotics and vaccination programs, infectious disease is no longer the leading cause of death in the western world.
Non-infectious disease is now responsible for the leading causes of death in both developed and some developing countries.