Strange Diseases That Science Never Explained

Medical science has come a long way over the years. We’ve found treatments for the Black Death; we created a vaccine for chicken pox; and we’ve done away with diseases like smallpox and rinderpest worldwide. But there are still some diseases science can't fully explain.

These mystery diseases range from epidemics of dancing dating back to the 1500s, to illnesses that once attacked cows and now target humans. Though some may seem almost comical, most are horrifying, incurable, and dangerous. The fact is, we may never know the causes of a few of these illnesses, but research is ongoing. And for many of these, we can only hope the answers come soon.

Of course, what we do know for now is downright fascinating. So learn more about some of the strange diseases science doesn't understand... yet.

Photo: Luciana Christante / flickr / CC-BY-NC-ND 2.0

  • Foreign Accent Syndrome
    Photo: Chris Hayden / flickr / CC-BY-NC 2.0

    Foreign Accent Syndrome

    Foreign Accent Syndrome is incredibly rare, and it has a variety of different causes. Typically occurring after head or brain trauma, a person will begin speaking in an accent different from their own and will be unable to stop.

    Some sufferers don't even realize they're doing it. Though FAS is an issue with the brain, scientists don't know why exactly it happens.

  • Burning Mouth Syndrome
    Photo: Jason Kuffer / flickr / CC-BY-NC-ND 2.0

    Burning Mouth Syndrome

    You know that feeling of your mouth being on fire when you eat spicy food? Well, imagine if that happened to you for no reason, all the time. Burning mouth syndrome occurs when a person has a chronic feeling of burning in their tongue, gums, or whole mouth with no apparent cause.

    A few treatments exist, but a healthcare professional is typically needed to manage it.

  • Schizophrenia
    Photo: David Ensor / flickr / CC-BY 2.0


    Schizophrenia should not be confused with multiple personality disorder, as popular media often interchange the two. Schizophrenia involves a plethora of different symptoms, many of which change from person to person, and include hearing voices, paranoia, disorganized speech and thought, and difficulty perceiving what is real.

    This disease has been studied for decades upon decades, but we still do not fully understand the cause, nor have we discovered any cure. 

  • Water Allergy
    Photo: Kit / flickr / CC-BY-NC 2.0

    Water Allergy

    Clinically called aquagenic urticaria, those who suffer from this allergy break out in painful and itchy lesions when exposed to water. That means no swimming, no bathing - even problems drinking water. We know the problem involves a genetic mutation, but researchers have no clue as to the cause.

  • Stiff-Person Syndrome
    Photo: gfpeck / flickr / CC-BY-ND 2.0

    Stiff-Person Syndrome

    A rare disease, stiff-person syndrome attacks the nervous system and can cause someone to stiffen all over gradually, but no one has figured out the primary cause. There is also no cure and no way to predict if someone will have it until symptoms appear. 

  • Peruvian Meteorite Illness
    Photo: ClaraDon / flickr / CC-BY-NC-ND 2.0

    Peruvian Meteorite Illness

    Back in 2007, a meteor crashed in the high plains of Peru. People who approached the site reported headaches, nausea, vomiting, and other symptoms. Twelve people at least were stricken with the illness, and many were treated for symptoms.

    While theories exist, the actual cause of the sickness is not known for sure.