9 Healthcare “Facts” Proven False but Still Repeated

Some Healthcare “Facts” Proven False but Are Still Repeated

Image Source: shutterstock.com

If you’ve ever been told to “wait an hour after eating before swimming,” or that “cracking your knuckles causes arthritis,” you’ve been fed one of the many so-called “health facts” that refuse to die. They spread from one generation to the next like whispered family secrets—except they’re totally wrong.

Despite all the science, studies, and experts yelling, “Please stop saying that!”, these myths cling to our collective consciousness. They sound reasonable enough to survive, and that’s what makes them so sneaky.

1. You Only Use 10% of Your Brain

It sounds inspiring, right? The idea that we have an untapped reservoir of genius just waiting to be unlocked? Unfortunately, neuroscience has completely crushed this one. Brain imaging studies show that nearly every part of your brain has some level of activity, even when you’re resting or daydreaming. The truth is, your brain is a full-time multitasker—if we really only used 10%, we’d probably forget how to breathe before finishing this paragraph.

2. Cracking Your Knuckles Causes Arthritis

Parents everywhere love this one. The sound might drive them crazy, but it’s not giving you arthritis. That satisfying pop? It’s just gas bubbles collapsing in the joint fluid—basically, your knuckles letting off steam. Multiple studies have found no connection between knuckle-cracking and arthritis, though chronic over-cracking might cause some swelling or weaker grip strength. So, while your coworkers might groan, your joints are perfectly fine.

3. Feed a Cold, Starve a Fever

This catchy rhyme has been circulating for centuries, but it’s based on zero medical science. The truth is, whether you have a cold or a fever, your body needs proper nutrition and hydration to recover. Skipping meals during illness can actually make you feel worse and slow your immune response. What your body really wants is rest, fluids, and balanced meals—not a diet plan that rhymes. So go ahead, sip some soup, drink water, and ignore this outdated advice.

Image Source: shutterstock.com

4. You Should Drink Eight Glasses of Water a Day

This “rule” has been splashed across wellness blogs and office break rooms for decades. The truth? There’s no magic number that fits everyone. Hydration needs depend on your size, activity level, and even the weather. Many of the fluids you need come from food, coffee, tea, and other drinks, not just plain water. So if you’re not hitting exactly eight glasses a day, don’t panic—you’re probably still doing just fine.

5. Going Out with Wet Hair Will Make You Sick

Moms everywhere have sworn by this warning, but colds are caused by viruses, not wet hair. You can sit in a snowstorm with damp locks and still stay healthy—as long as you haven’t picked up a bug from someone else. While being cold might weaken your immune system slightly, it doesn’t create illness. The only thing you risk by heading out with wet hair is a bad hair day, not the sniffles. Still, maybe keep a hat handy for comfort’s sake.

6. Sugar Makes Kids Hyper

Every parent knows the chaos of birthday parties and Halloween, and it’s easy to blame the candy. But multiple scientific studies have shown no link between sugar consumption and hyperactivity in children. What’s really happening is excitement—the party atmosphere, the friends, the fun. Sugar might give a brief energy bump, but it’s not the wild behavioral switch it’s been made out to be. Turns out, the “sugar rush” is more myth than molecule.

7. Shaving Makes Hair Grow Back Thicker

Here’s another myth that refuses to quit. Shaving doesn’t change the thickness, color, or growth rate of your hair—it just feels different when it grows back. When hair is cut bluntly at the surface, the ends are less tapered, giving the illusion of thicker stubble. But it’s just an illusion, not a transformation. Your genetics control hair growth, not your razor. So shave away without fear of morphing into a woolly mammoth.

8. Sitting Too Close to the TV Will Ruin Your Eyes

Generations of parents warned kids to back away from the television, but it turns out the screen isn’t the villain here. Watching too closely might cause temporary eye strain, but it won’t cause permanent damage. Modern screens emit far less radiation than the bulky TVs of the past, and our eyes naturally adjust focus over time. If your eyes feel tired, just take a short break. So no, your childhood Saturday morning cartoons didn’t secretly sabotage your vision.

9. You Shouldn’t Wake Someone Who’s Sleepwalking

Movies love this myth—it adds drama when someone stumbles through the dark like a ghost. But medically speaking, waking a sleepwalker isn’t dangerous—it’s just tricky. The person may be confused or startled, but they won’t suffer harm. In fact, letting them wander around unsupervised can be far riskier. The safest move is to gently guide them back to bed or wake them calmly if they’re heading for danger. So next time you catch a midnight wanderer, don’t panic—just steer them back to dreamland.

Old Myths Die Hard

It’s fascinating how some health myths survive long after science has disproven them. Maybe it’s nostalgia, or maybe we just love simple explanations for complex things. Either way, separating fact from fiction matters—especially when it comes to your health. Knowledge evolves, and so should the “truths” we pass along to others. Have you ever believed one of these myths—or maybe caught someone else spreading them?

Share your thoughts, stories, or your favorite debunked “fact” in the comments below.