Serotonin syndrome (aka serotonin toxicity) is often misunderstood, causing both unnecessary worry and missed warning signs.

Alpha-gal syndrome is a strange tick-borne illness that induces an allergy to a specific type of sugar found in red meat.

Havana syndrome is a mysterious ailment that began afflicting U.S. diplomats and intelligence officers in or near the U.S.

In the years leading up to his death Tuesday, former CIA Director James Woolsey suffered from the mysterious ailment known as ...

The mysterious illness can cause concussion-like symptoms, tinnitus, dizziness, and more.

The spread of the lone star tick and alpha-gal syndrome, the red-meat allergy its bite can cause, has alarmed many Americans.

Main character syndrome is the perception that your life is a story or a movie where you’re the central character. A term that was born on social media, it’s not a true syndrome or mental disorder.

Cannabinoid hyperemesis syndrome causes abdominal pain, nausea and vomiting that is serious enough to send people to the emergency room.

There’s a type of food allergy you might not expect because it doesn’t come from foods like peanuts, dairy, wheat or soy -- ...

New research, led by scientists from the Seaver Autism Center for Research and Treatment at Mount Sinai and published June 28 in Autism Research, has estimated that Phelan-McDermid syndrome (PMS) ...

A Knightdale mom is on a mission to raise awareness of a rare and serious condition called Stevens-Johnson syndrome after her ...