Three infectious diseases ruin the holidays. A Christmas baby is born, but doctors find her brain was infected in utero. An infection upturns a woman’s Hanukkah. A school teacher's Thanksgiving & Christmas are disrupted by seizures.

Three diseases disrupt the lives of three families. One eats the leg of a teenage boy, and may kill him. Another afflicts a couple, and tears their lives apart. And insidious worms hijack an eight-year-old girl's eyeball.

A boy vomits his own fecal matter. A teenager contracts one of the most feared diseases on the planet. A young girl is quarantined with an unknown illness. What monsters are hiding in the backyard?

Monsters are hiding where you’d least expect. A child is struggling to breathe, a man has something living in the last place he’d want and a woman with weight gain confounds experts. Who are the monsters inside them?

A mysterious infection brings a tough football player to his knees. To her horror, a stay-at-home mom has parasites devouring her eyeball. And a marina dock master is attacked by sea creatures!

A family's cruise vacation turns into a living nightmare when their two year old swallows a sinister monster. A mother of two is plagued with a mysterious infection. Deadly parasites hijack the brain of a six-year-old boy.

Monsters can hijack our bodies in any number of ways. A man breaks out in a mysterious painful rash. A woman experiences bouts of piercing pain in her throat. A teen girl is left debilitated by strange spells of dizziness and fatigue.

Three families are turned upside down by deadly monsters. A 4-year-old boy is plagued by crippling pain. A college student with a small cut ends up fighting for her life. A woman is driven to insanity by an intruder in her own body.

Three infectious diseases ruin the holidays. A Christmas baby is born, but her brain was infected in utero. A woman sees a dark shadow move across her eye & believes it's a worm, & a man is left with an unwanted Christmas surprise.

A young girl is brought to the hospital with stabbing pains in her scalp. A wife and mother is struck down by a severe string of mysterious symptoms. A deadly invader turns a relaxing vacation into a nightmare.

A man falls comatose. A college student's sore throat turns deadly. A woman's bizarre symptoms confound experts.

A man experiences bizarre swelling around his eye. A 12-year-old girl falls mysteriously ill. A young woman is struck by a bizarre set of symptoms that leaves her on the verge of madness, and no one can understand why.

An infant falls mysteriously ill. A biology professor becomes an unexpected host. A family man is brought to the brink, all in this episode of Monsters Inside Me.

A woman who has recently given birth is in critical condition. A young boy has signs of a mysterious infection that no antibiotics can cure. A young man feels excruciating pain and doctors discover something has invaded his brain.

A boy is struck down with a strange condition. A woman has bizarre symptoms that push her to the brink of madness. A toddler falls into a trance-like state.

A teenager develops mysterious blotchy sores. A tough athlete is struck down by a rare disease. A woman battles strange bouts of vomiting.