What is an internal parasite?

What is an internal parasite? - Animal Hospital of Statesville

It's a parasite that lives inside. A mosquito injects these worms into the body of the cat, and it migrates toward the lungs.

What is an internal parasite? - Four Paws At Fulshear

An internal parasite is anything that lives inside of you, such as intestinal parasites, heartworms, tick-borne diseases, blood-borne diseases, and fungal diseases.