When to use pandemic vs. epidemic vs. whatever?

I looked at the dictionary definitions but I don’t really get the distinction. Could someone explain it in terms of: Use “pandemic” when it’s this situation, use “epidemic” when it’s that situation, use some other term in some other situation.

As I learned it in college, a Pandemic is a worldwide phenomena while an Epidemic is much more limited it scope. As far as what determines whether something is worldwide in scope or not is anybody’s guess.

For example, if there was a flu that just impacted North America I would call it an epidemic. If the same flu was found in Euope, Asia and North America I would consider that a pandemic. YMMV.

That’s it, a pandemic is over a greater area.
“Epi” means visiting while “pan” means everyone
Here’s the dictionary links:
epidemic pandemic

The way I understand it: An epidemic refers to a disease with hugely more local occurrences than normal. So let’s say 10 cases/year of x-itis in Freedonia is normal, where 100 cases is normal in Sylvania. If next year Sylvania has 101 cases, it’s not an epidemic, but if ther eare 50 cases in Freedonia, it is.

By that definition, if 1 case of smallpox occurs in North America, it’s an epidemic.

A pandemic is where there are epidemics occur in many locales.

I don’t think anyone would refer to one case of smallpox as an epidemic.

In order of size, there’s an isolated case, then an outbreak, then an epidemic, then a pandemic. HIV, for instance, could accurately be described as a pandemic. There was a cholera epidemic in South America several years ago, but since it never spread to other parts of the globe, it never became pandemic.

See, I figured that’s what it meant, but the news stations reporting the latest it’s-gonna-kill-us-all! disease insist on saying “worldwide pandemic”, which seems somewhat redundant.

The triad:

Endemic: a disease that exists permanently in a particular region or population. Malaria is a constant worry in parts of Africa.

Epidemic: An outbreak of disease that attacks many peoples at about the same time and may spread through one or several communities.

Pandemic: When an epidemic spreads throughout the world.

Thanks all. It seems much simpler now. (And I think Qadgop nailed the whatever as “endemic”.)

I lifted that example from a radio interview I heard a few weeks ago with a public health official. Certainly, in common use the word “epidemic” is a dramatic word - no one would that word to describe one case of anything. But it’s like the way no one calls a tomato a fruit, even though technically it is.

Dunno, perhaps the interviewee simply contrived the smallpox example for emphasis on the “higher than expected” aspect of the word.