Five Medical Myths Debunked

What with the country’s current obsession with fake news, we decided to jump on the bandwagon and gift you with some debunked medical myths this holiday season. Some of these pieces of misguided advice have plagued us for decades, while others are newer ideas about how to stay in good health. Either way, the science is in, and it declares each of these five statements to be false:


  1. Don’t let someone sleep after they’ve suffered a concussion.

This fear likely evolved out of a misunderstanding about the “lucid interval,” a period of time after someone wakes up from being unconscious and seems fine, while in actuality, they are experiencing bleeding within their brain.[1] However, this is a rare occurrence, and if a patient needs to be watched that closely, a doctor will most likely admit them to the hospital.[2] Most medical professionals say that it is fine to let people sleep after suffering a head injury, and many even suggest it.[3]

  1. Reading in the dark will ruin your vision.

While for decades, children have been yelled at for reading in the dark, being warned that they will ruin their eyes, this claim doesn’t actually hold water. Reading in low light is more difficult because our ability to see fine details is diminished,[4] which can lead to more eyestrain, fatigue, and potentially, headaches.[5] However, this discomfort is only temporary, and no long-term damage to eyesight has been proven.[6]

  1. Drink eight glasses of water a day.

The advice to drink eight 8-ounce glasses of water a day, or the 8×8 rule, possibly originated in 1945, when a research report was released stating that the average person needed to consume one milliliter of water per calorie of food they consume.[7] Based on a daily 2,000 calorie diet, this adds up to 2,000 milliliters, or roughly 64 ounces.[8] However, this report also declared that much of this water could be obtained from food and other liquids consumed – a point the public didn’t seem to focus in on.[9] No scientific studies have found evidence to support the 8×8 rule, and while there may be special circumstances that call for it (such as after vigorous workout, especially in hot climates), [10] each person’s water needs differ, and our bodies are programmed to let us know when we’re thirsty without us actively tracking water intake.[11]

  1. Stress and spicy food can cause ulcers.

Peptic ulcers, which occur along the lining of the stomach and other parts of the small intestine, were once thought to be caused by lifestyle stresses or spicy food.[12] However, it is now recognized that these ulcers are caused by the bacterium Helicobacter pylori.[13] While stress and diet can irritate an ulcer, they cannot cause one to develop.

  1. You can get the flu from a flu shot.

Although you can develop a low-grade fever in response to a vaccination, the idea that you could contract the flu from the vaccine is a myth.[14] The misunderstanding comes from the fact that vaccines are created from the offending viruses themselves; however, the flu shot only consists of an inactive, dead version of that virus.[15] This means that while the virus can’t make you sick, it does stimulate your body to create antibodies that will protect you if you come in contact with the active virus later.[16] Though no vaccine is 100% effective, if you contract the flu after receiving the shot, you can’t blame it on the vaccine.[17]


These five examples of medical myths are just the tip of the iceberg; it’s important to recognize that media coverage of politics isn’t the only example of “fake news” affecting our perceptions of the world. Be aware of where your medical advice comes from, and always check your facts with certified medical professionals.



[1] Hammond, Claudia, “Should you let someone with concussion fall asleep?”, BBC, June 17, 2016,

[2] McCoy, Krisha, “True or False: A Person With a Serious Head Injury or Concussion Should be Kept Awake,” PT & Me, Aug. 16, 2016,

[3] Ibid

[4] “Reading in the Dark Will Ruin Your Eyes,” Patty Vision Centers, Feb. 15, 2016,

[5] O’Connor, Anahad, “The Claim: Reading in the Dark Will Damage Your Eyes,” The New York Times, July 4, 2006,

[6] Ibid

[7] Palsdottir, Hrefna, “Drink 8 Glasses of Water a Day: Fact or Fiction?”, Healthline, Nov. 8, 2016,

[8] Ibid

[9] Ibid

[10] Valtin, Heinz & Sheila A. Gorman, “‘Drink at least eight glasses of water a day.’ Really? Is there scientific evidence for ‘8 x 8’?”, American Physiological Society, 1 Nov. 2002,

[11] Becker, Rachel, “You really don’t need to drink eight glasses of water each day,” The Verge, May 10, 2017,

[12] Stoppler, Melissa Conrad, “Does Stress Cause Ulcers?” MedicineNet, n.d.,

[13] Nixon, Robin, Elizabeth Peterson, and Karen Rowan, “25 Medical Myths That Just Won’t Go Away,” Live Science, Oct. 18, 2016,

[14] Ibid

[15] Davies, Helen, Marjorie Dorfman, Mary Fons, Deborah Hawkins, Martin Hintz, Linnea Lundgren, David Priess, Julia Clark Robinson, Paul Seaburn, Heidi Stevens, and Steve Theunissen, “9 Medical Myths,” How Stuff Works, n.d.,

[16] Ibid

[17] Ibid