5 Amazing Breakthroughs Discovered by Accident

Chances are, the next time you get sick, you won't want to hear your doctor utter the words "mistake" or "accident." But if it wasn't for mistakes and accidents, some of the very things you rely on to stay healthy or help you heal may never have been discovered. Here, a look at five accidental breakthroughs that have changed the way doctors practice medicine.

1. X-Rays:

Imagine breaking a bone and not having your doctor perform an X-ray to show where the fracture occurred. That could have been the case had German physicist Wilhelm Roentgen never accidentally discovered that X-rays can be seen through solid objects. Roentgen was experimenting at the time with cathode-ray tubes (CRT), which are now most commonly known for their use in TV screens. During his experiments, Roentgen noticed that some light was able to penetrate cardboard, wood, and even his hand. He took early X-rays of the bones of his wife's hand and was awarded the Nobel Prize in 1901 for his work.

2. Penicillin:

Alexander Fleming's unexpected discovery of penicillin is possibly one of the most famous. Fleming was conducting research on the flu and notice that mold was growing in one of his petri dishes. Upon closer inspection, he realized that the area with the mold had no bacteria. After further tests, Fleming determined that penicillin could be used to fight bacterial infections, and it is still used today to treat pneumonia, and ear, skin, and throat infections.

3. Smallpox vaccine:

Over the centuries, smallpox may have killed more people than all other contagious diseases combined, according to the National Institutes of Health. It was a particularly deadly disease in the 18th century--until British scientist Edward Jenner stumbled upon the vaccine. Jenner had overheard a milkmaid say the people who had cowpox, which was relatively harmless, never contracted smallpox. Armed with this information, Jenner experimented by infecting an 8-year-old boy with cowpox and then exposing him to smallpox. Thanks to Jenner's vaccine, smallpox has been virtually eliminated today.

4. Viagra:

A relatively recent accidental discovery, the active ingredient in Viagra was found to be an effective treatment for erectile dysfunction even though it was intended to be a cardiovascular drug. During the testing phase, scientists at Pfizer realized that it was not effective in treating heart ailments, but they wanted to continue to study one of the drug's unexpected side effects. In 1998, the FDA approved Viagra as the first oral treatment for men with erectile dysfunction.

5. Coumadin:

The blood thinner warfarin, also known by its brand name Coumadin, has an interesting history. It was once also used in rat poisons, discovered when farmers noticed that their cows were dying after eating a type of clover. It was later realized that a particular chemical in the plant prevented their blood from clotting and caused them to hemorrhage. Since the chemical was capable of killing cows, they began using it to kill rats. However, it was later discovered that in proper doses, warfarin could be beneficial to people who are at risk of blood clots, and in 1952, it was first used as a blood thinning agent on humans.