25 Childhood Habits That Affect Your Adult Health

Sleeping with the light on probably wasn't the best idea.

Kids aren't typically the most health-conscious individuals. At the park, they eat dirt; at school, they chew on pens; back at home, they consume hours of television. And let's face it: No matter how healthy we like to think we are now that we're adults, there's almost no doubt that we partook in at least a few of these harmful activities when we were kids.

Unfortunately, these childhood habits don't just affect us in our youth. In fact, several of the things we did as children have huge impacts on our health as adults. From sleeping with the lights on to sucking your thumb, these are the habits that might catch up to you down the road.

Sleeping with the light on.

Little Boy Sleeping with the Lights On Childhood Habits that Affect Adult Health

Many children are afraid of the dark and sleep with a light on. However, if you did this as a kid and continue to do it as an adult (even if you've graduated to simply leaving the television on), you could have set yourself up for trouble. One 2018 study published in the American Journal of Epidemiology found that people who are exposed to light at night had a significantly higher risk of depression compared to those who slept in the dark.

Picking your nose.

Little Girl Picking Her Nose Childhood Habits That Affect Adult Health

Nose-picking is a bad habit that some adults carry with them from their childhood. And not only is it embarrassing, but it also poses some potential health risks. In one 2006 study published in the journal Infection Control & Hospital Epidemiology, researchers tested 324 subjects and found that nose pickers were 51 percent more likely to carry S. aureus—a strain of bacteria responsible for skin and respiratory tract infections—than those who kept their fingers out of their nose.

Lugging around a heavy backpack.

Child Carrying a Heavy Backpack Childhood Habits that Affect Health

The heavy schoolbag from your childhood could be behind those aches and pains you feel today. One 2004 study published in the Journal of Pediatric Orthopedics found that carrying a heavy backpack was associated with chronic back pain and potentially permanent injuries. "This is truly alarming," said David Siambanes, MD, the chief investigator for the study. "Research has shown that adults with severe back problems often had pain as kids. You can suffer all your life from this kind of injury."

Watching too much television.

Little Girl Watching Television Childhood Habits That Affect Health

Per one 2015 study published in the journal Cerebral Cortex, kids who spend more time in front of the TV have lower verbal IQ scores. That's because watching a significant amount of television is associated with a thickening in the frontopolar cortex, an area of the brain associated with intellectual abilities. Another 2007 study published in the journal Pediatrics found that watching too much television as a child could lead to attention problems in adolescence.

Sucking your thumb.

Little Boy Sucking Thumb Childhood Habits That Affect Health

Babies and children love to suck on their thumbs as a means of comfort. And while most individuals grow out of this habit, it can leave behind some side effects that take a long time to correct. For instance, according to the American Dental Association (ADA), thumb sucking can disrupt permanent teeth as they align during childhood and can even impact the roof of the mouth.

Biting your nails.

african american girl with glasses and overalls nervously bites nails, bad childhood habit

Nail biting is another coping mechanism that children and adults alike rely on when they feel nervous. However, if you've held onto this habit from your childhood, you should probably eliminate it as soon as possible. In one 2014 study published in the international journal Acta Dermato-Venereologica, researchers found that people who bit their nails had a lesser quality of life compared to those who didn't engage in the habit. These people also had visible nail abnormalities.

Drinking a lot of juice.

Girl Drinking a Juice Box Childhood Habits that Affect Health

Your childhood habit of sipping on sugary juices could have had a lasting effect on your teeth. According to the American Dental Association, the copious amounts of sugar in these beverages produce acid that damage teeth, create cavities, and result in erosion. And if cavities are left untreated or aren't filled properly, they can lead to painful root canals or crowns later in life.

Being too sedentary.

Sad Kid Playing Soccer Childhood Habits that Affect Health

Healthy activity levels as a child lead to healthy activity levels as an adult. "It's important to encourage movement in children, even if it's not formal exercise or organized sports, to help them grow up into adults that make movement and exercise a priority in their lifestyle," says Maryann Walsh, MFN, RD, a registered dietitian. Fortunately, it's never too late to start leading a less sedentary life.

Holding you breath during tantrums.

Angry Child With a Red Face Holding His Breath Childhood Habits that Affect Health

Hopefully, you didn't do this too often as a child. Per one 2012 analysis published in the journal Sports Medicine, regularly holding your breath can cause a collapse of the lungs, cardiac arrest, blackouts, and other serious long-term health issues. So really, you were just sticking it to yourself by doing this.

Sucking on a pacifier.

Baby Sucking on a Pacifier Childhood Habits that Affect Health

Similar to sucking your thumb, sucking on a pacifier for a significant period of time as a child can seriously damage your teeth. Per one 2006 analysis published in the International Journal of Orthodontics, "pacifier use beyond the age of three contributes to a higher incidence in anterior open bite, posterior crossbite, and narrow intercuspid width."

Sniffing markers.

Colorful Markers Childhood Habits that Affect Health

Sniffing markers is a childhood habit that should be taken seriously. In fact, back in 1990, the Texas Prevention Partnership even created a series of posters warning kids about the dangers of "huffing," some of which include losing brain cells, developing lung disease, and developing heart complications.

Chewing on toys.

Child Chewing on Toys Childhood Habits that Affect Health

Unless a toy is specifically designated as something that can be used for teething, then make sure that your kid isn't chewing or sucking on it. The Centers for Disease Control and Prevention (CDC) warns that toys—imported and antique ones especially—can contain lead, which is harmful both in the short-term and long-term when ingested.

Following your parents' overly-restrictive diet.


There is such a thing as being too healthy, and it can take a serious toll on kids' health and development. "I have seen lots of children with parents that have orthorexia—an obsession with eating healthy that becomes excessive—develop poor relationships with food," says Walsh. "Certain foods are forbidden to [these children], which only makes them more enticing as they get older. This can lead to children developing disordered eating patterns, whether it be binge eating, anorexia, or even orthorexia like the parent(s)."

Not standing up for yourself.

Child Getting Bullied Childhood Habits that Affect Health

Were you bullied as a child? If so, it might be taking a toll on your mental health as an adult. That's according to 2013 research published in the journal JAMA Psychiatry, which concluded that being bullied as a child is correlated with being depressed (and needing to be treated for depression) as a young adult.

Not wearing enough sunscreen.

Mom applies sunscreen to child's back on beach, bad kid habits

Did you enjoy a little too much fun in the sun sans sunscreen as a kid? Well, as an adult, you may be suffering the consequences. One 2017 study published in the journal Photochemistry and Photobiology found that basal cell carcinomas (BCC) diagnosed later in life were most commonly the result of too much sun exposure during childhood.

Not learning how to cook.

Little Girl Mixing in a Bowl Cooking Childhood Habits that Affect Adult Health

If you never asked your parents to show you some simple cooking techniques as a kid, it could catch up to you later. "While you don't need to be a five-star chef, not demonstrating any sort of cooking or meal preparation in front of children can lead them to not have the desire to learn simple meal prep or cooking techniques and rely on fast food, eating out, or prepared meals from supermarkets," explains Walsh.

Bad tooth brushing habits.

Child Doesn't Want to Brush his Teeth Childhood Habits that Affect Health

Children are easily impressionable. And unfortunately, that means if your parents maintained a few poor habits when you were growing up, you might have acquired them too. One 2011 study published in the Journal of Dental Research, for instance, found that when a mother has poor oral hygiene, her child or children are more likely to have poor oral health as well as they approach adulthood.

Swallowing toothpaste.

Little Girl Brushing Her Teeth Childhood Habits That Affect Health

When you visit the dentist, you often undergo a fluoride treatment in order to prevent decay and strengthen your pearly whites. However, there's a reason why the dentist always warns you not to swallow the stuff. As one 2017 study published in the Iranian Journal of Basic Medical Sciences warns, ingesting large amounts of fluoride can have "toxic and lethal effects." Fortunately, if you haven't experienced any negative side effects yet, you're probably in the clear.

Being overweight.

Kid Being Measured For Obesity Childhood Habits that Affect Health

We all had a little bit of baby fat, but a child should only carry so many extra pounds. The CDC warns that obese children are more likely to grow up to become obese adults with health conditions like heart disease and type 2 diabetes.

And one 2017 study published in the British Journal of Cancer found that subjects who reported being overweight at 20 years old were anywhere from 60 to 80 percent more likely to develop esophageal or stomach cancer later in life than those who are, and always have been, a healthy weight.

Not getting enough sleep.

little girl asleep in bed, stay at home mom

Your habit of staying up past your bedtime as a kid could impact your weight now that you're older. When researchers for one 2008 study published in the journal Pediatrics followed 1,037 children from birth until their 32nd birthday, they found that each hour of sleep lost during childhood was associated with a 50 percent greater risk of obesity in their 30s.

Playing in heavily polluted areas.

Pollution in the Skies in Thailand Childhood Habits that Affect Health

Just like the rest of your body, your lungs don't fully develop until long after birth. The problem? When a child is exposed to polluted air, the American Lung Association warns that they are at a greater risk of reduced lung growth, "which may never recover to the full capacity." In these instances, the reduced lung function is similar to what's seen in children who grow up with smoking parents. And speaking of…

Spending time with smokers.

Parent Smoking in the Car in Front of Their Child Childhood Habits that Affect Health

Living in a household with a parent who smokes doesn't just impact your health as a child; it can also affect your decisions as an adult. In fact, according to Cancer Research UK, children who witness their parents smoking are three times more likely to take up the bad habit themselves as an adult compared to those with parents who never smoke.

Chewing on pen caps.

White boy chews pen cap at desk, bad child habit

When you got bored or anxious in class as a kid, you might've gotten into the habit of chewing on your pen cap. Unfortunately, that wasn't so great for your teeth. As one 2012 study published in the Journal of Pharmacy & BioAllied Sciences explains, "Habits that might contribute to cracked teeth are clenching or grinding, chewing ice, pens, hard candy, or other similar objects."

Being chronically stressed.

young white boy closes eyes and covers ears as he sits on the floor, bad kid habits

Were you constantly stressing about things like friends and schoolwork as a child with little to no support from the adults around you? If so, this may be the reason why you are suffering from—or will suffer from—serious diseases like heart disease and chronic lung disease. Per one 2015 report published in Yale Nursing Matters, toxic stress during childhood is associated with both physical and mental problems later in life.

Overusing social media.

Little Girl on Her Smartphone Childhood Habits that Affect Health

Depending on how old you are, you may or may not have had social media growing up—and if you didn't, it's probably a good thing. According to one 2018 study published in the journal Nature Communications, today's adolescents spend anywhere from six to nine hours a day on social media platforms like Instagram, Facebook, and Snapchat. And while these apps are entertaining, the study authors warn that excessive social media use in teenagers can make them less patient, more reward-driven, less confident, and more prone to mental health issues throughout the remainder of their lives. And for more Facebook faux pas, here are 20 Social Media Mistakes You're Making.

To discover more amazing secrets about living your best life, click here to follow us on Instagram!