what are global diseases???!!?

Global diseases are those that affect "populations" and are not limited by national or geographic borders.

Check the world health organisation for a rundown (they've some handy fact sheets too) that you'll find useful.

As a few ideas, it's sometimes helpful to split these things into specific disease groups affecting the spectrum of global economics. For example first world nations are troubled by diseases of their own affluence (diabetes, heart disease) , third world nations are troubled largely by infectious diseases (like the bloke above mentioned - Dengue, HIV , Tuberculosis) - these are driven by large populations without first world infrastructure in less than sanitary conditions - contributing to the spread of disease. These populations generally don't live long enough to get heart disease (!)

Interestingly, take a 10th generation somalian and feed him an American diet and he'll develop diabetes, cholesterol, and hypertension faster than you can shake a stick. Take a NASDAQ CEO to China and he can catch avian flu as quick as you can say "achoo".

Another way to look at things is 'pandemics' - check the global spread of influenza recently and match it to the spread and scale of say, the spanish flu (Google will help you)

It's easy - put your own spin on it. We're all human, in the right conditions we'll all get the same diseases.

BTW : It's spelt "PLEASE"

A global disease is a disease which can be found almost anywhere in the world. There are many diseases that fall into this category and if you search for "global disease" you'll get many good results. I'll name two for you here, HIV/AIDS and Dengue Fever. Good Luck