Endemic vs. Epidemic – What’s the Difference?

If you are a researcher for the World Health Organization, you will need to know how to describe the various diseases and populations that you study. Two words that describe diseases, endemic and epidemic, may seem similar, but they are actually two different words with separate meanings.

To make matters even more confusing, both of these words can be used as multiple parts of speech. Still, if you want to maintain your credibility as one of the globe’s foremost authorities on human health and wellness, you will need to know how to use these words appropriately.

What is the Difference Between Endemic and Epidemic?

In this post, I will compare endemic vs. epidemic. I will use each of these words in at least one example sentence, so that you can see how they look in context. I will also show you a mnemonic device that makes choosing either endemic or epidemic a much easier task.

When to Use Endemic

endemic versus epidemicWhat does endemic mean? Endemic can be a noun or an adjective.

As a noun, endemic means a disease that is regularly found  in a population of people or certain area. It can also refer to a species that is always present in a region.

Here are some examples,

  • Advancements in modern medicine have eliminated many endemics.
  • Chickenpox is an endemic in the United Kingdom.

As an adjective, endemic describes the quality of always being present exhibited by some diseases and species.

Here are two more examples,

  • Mosquitos that are not endemic to Brazil have been the target of genetic modification to reduce their population.
  • Malaria is a disease endemic to some regions in Africa.

When to Use Epidemic

Definition of epidemic definition of endemic definitionWhat does epidemic mean? Epidemic can also be a noun or an adjective.

As a noun, epidemic means a disease that spreads rapidly and causes devastation.

Here are two examples,

  • There was an epidemic of polio in the United States in the early 20th century.
  • The worldwide epidemic of the Zika virus in 2015-2016 caused the Pope to make controversial comments regarding the moral permissibility of birth control.

An an adjective, epidemic refers means of, relating to, or of the nature of an endemic.

Here are two more examples,

  • Epidemic diseases sometimes kill many people, but sometimes kill no people.
  • This disease has now reached epidemic proportions.

Of the two words, epidemic is much more common.

Trick to Remember the Difference

Define epidemic and define endemicDespite their similar names, remember epidemic vs. endemic is actually quite easy.

  • If you are describing something that spreads rapidly, choose epidemic.
  • If you are describing something that is always present, choose endemic.

Since epidemic and rapid each contain the letter P, this should be an easy decision to make.


Is it endemic or epidemic? Both endemic and epidemic can be used as adjectives and nouns.

  • Endemic describes a disease or condition that is regularly found among particular people or in a certain area.
  • Epidemic describes a disease that spreads rapidly or the quality of spreading rapidly.

The words epidemic and rapid are both spelled with the letter P, so choosing epidemic to describe something that spreads rapidly should be a simple matter.

Careful word choice can often make the difference between strong writing and an embarrassing blunder.

Be sure to check this site any time you have questions about confusing words, and if you get stuck choosing epidemic or endemic, check back with this article.