Disease can start from different factors that influence our internal balance. These can be things from external influences or internal factors. External influences can be pathogens and internal factors can be genetics.
it is important because they could start finding out the germ that cause a certain disease
no its a symtom that could be caused by a disease
well to start you could get some nice mould growth and a enhanced percent of fungus in your bloodstream, you also might get a disease. xD
could be anything depending on the disease.
they could not work if they had disease
It can keep you from catching a disease that could kill you. And since you did not get the disease, you will not be giving it to someone else who could die from the disease.
People with the disease seem to be very inflexible, and start to run slower as the disease becomes worse.
Every disease is an illness but not every illness is a disease (A disease is not a virus, parasite, etc but an illness could be)
Ebola
It can get a disease from somewhere.
It could but this is not a symptom of the disease.
its not a disease, its a mental condition. You dont just "get it", you develope it.