As medicine has advanced over the centuries, diseases have come and gone, but not always because they've been eradicated. Many times, widely diagnosed maladies -- some of them supposedly debilitating or deadly -- turned out not to exist when new technologies allowed a closer look. Other times, diseases simply vanished when rigorous skepticism was dutifully applied.

Chronic Lyme disease, chronic candidiasis, and non-celiac gluten sensitivity are a few questionable conditions that persist today. Time and evidence will likely "cure" them for good.

Here are five historical diseases that were eliminated by scientific scrutiny.

Suppressed Gout. Throughout Charles Darwin's adult life, he was plagued by sometimes debilitating health issues. Turning to a variety of doctors for help, he received a menagerie of diagnoses. One of these diagnoses was "suppressed gout." Gout, of course, is a genuine condition, characterized by severe pain, redness, and swelling in joints, often the joint at the base of the big toe. Suppressed gout, however, was completely fabricated. In the 19th century, many doctors believed gout was caused by an accumulation of toxic substances. Some further blamed these substances for causing a host of other discomforting symptoms. Suppressed gout thus became a diagnosis of convenience.

Joseph Dalton Hooker, a legendary British botanist and Darwin's closest friend, was highly skeptical of suppressed gout. In a correspondence with Darwin from January 1865, he wrote:

"What the devil is this 'suppressed Gout' upon which doctors fasten every ill they cannot name? If it is suppressed how do they know it is gout? If it is apparent, why the devil do they call it suppressed? I hate the use of cant terms to cloak ignorance."

Railway Spine. Train travel was common in the 19th century, as unfortunately, were train collisions. Rickety rails, coupled with shoddy construction of passenger cars, rendered rail travel a decidedly more hazardous form of transportation compared to today. This situation resulted in a number of injuries, but it also brought forth opportunists hunting for an easy profit. Doctors all over the world found themselves listening to patients claiming they had been injured in crashes, yet showing no signs of actual ailment. The term "railway spine" was created for these cases. Railroad companies adamantly denied the malady's existence, yet were forced to pay thousands of dollars to supposed sufferers. Railway spine created quite a controversy in certain sects of the medical community. Now defunct, the disorder could very well have existed. Today the symptoms might be classified as whiplash or PTSD.

Status Lymphaticus. In the early 1900s, status lymphaticus reportedly killed thousands of children and was even regarded as "the most important problem in medicine." Today, most doctors have never heard of it, and that's for a good reason: it never existed.

The supposedly deadly disease was linked to a tiny gland nestled near the heart and lungs: the thymus. Now known as a key part of the immune system, the gland was not always held in such high regard. As the cause of status lymphaticus, the thymus was thought to occasionally grow out of control, pressing upon the heart and the lungs until the victim suffocated from the inside. Closer, skeptical scrutiny eventually disproved the condition in 1931.

Ovariomania. Commonly called "Old Maid's Insanity", ovariomania was a condition usually diagnosed amongst women at the early stages of menopause, although it was sometimes diagnosed even earlier. Some doctors believed that tumors in the ovaries prompted bouts of insanity. As influential Scottish psychiatrist Sir John Batty Tuke described:

"Women who for years have been carrying tumours, when they arrive at the change of life develop aberration of intellect, and not unfrequently the character of their illusion is marked by sexuality and erotomania; they think that they are pregnant, or that they are visited at night by men."

These tumors never actually existed, but that didn't stop 19th century surgeons from conducting as many as 150,000 oophorectomies on women, involving the removal of the ovaries.

Intestinal Autointoxication. There's poop inside you. Right now. But though disgusting when outside the body, feces are fairly benign inside. Tucked away within the colon awaiting excretion, there's little harm that poop can do. Physicians of the past weren't so sure however.

Dating back to ancient Egypt, medical "professionals" once entertained the notion that putrefaction of feces inside the body causes disease. The toxins produced supposedly shortened lifespan and sparked a host of maladies. While this hypothesis was firmly debunked decades ago, the premise still fuels a cornerstone of the natural health industry: the colon "cleanse."

(Image: Maull and Polyblank)