It's an agonizing process to remove these creatures.

After a woman suffers having cysts surgically removed from her right breast, things get even worse when surgical sponges are accidentally left inside of her.

A dream vacation to South America becomes a nightmare when a man's face begins to be eaten away by a parasite.

Tara keeps feeling stabbing pains in her scalp, so she investigates the Internet for answers. What she finds is almost unbelievable - botflies. She decides to cut open her scalp.

Boil-like legions lead to a diagnosis of lung cancer, just in time for Christmas. But during surgery, doctors are surprised to find a different sort of infection.

Found in contaminated food and water, Entamoeba histolytica is a parasite that feeds on living cells in the human gut.

After eating some raw sushi, a woman begins a fight for her life as a mass containing parasitic worms creates a blockage in her colon. The woman has Anisakiasis, a disease caused by Anisakis worms.

A disease begins eating a boy's face from the inside, forcing doctors to begin removing the infected flesh to save his life.

A happily married couple's trip to New York becomes a nightmare when they learn that they have been infected with the Bubonic Plague, not only putting their lives in danger but anyone who comes into contact with them.

Leishmaniasis kills skin cells in mass numbers, causing prominent skin sores. In extreme cases, it attacks the face itself, leaving the victim disfigured.

The Leishmania parsite feeds directly on the vital organs from the inside-out. It's spread through infected sand flies.

Acanthamoeba is a voracious parasite that enters the body through the skin or the nose, then devours brain cells.

While swimming with a friend a man has a seizure and collapses. Shortly after, he finds out that a pork tapeworm has been slowly eating away at his brain!

Even dead, the larvae of parasitic roundworms can cause river blindness, or Onchocerciasis. These parasites are transmitted through the saliva of blackflies.

Burrowing through the skin and internal organs, gnathostoma worms can eventually cause paralysis and death.

The pork tapeworm is a particularly vicious parasite because it can end up in the most important organ in the human body: the brain.