Due to the plethora of health trends and self-proclaimed health "experts," it can be challenging to trust the information you hear about your physical and mental well-being. However, by relying on research and data, you can sift through the nonsense and uncover the hard truths about your health. To help you, we've compiled 10 surprising but 100% true facts about everything from your body to your brain.

#1. Urinating in a pool is dangerous for your heart.

Though definitely unsanitary, peeing in a pool might seem harmless for your health. After all, urine is sterile, as is chlorine. As it turns out though, urine and chlorine create dangerous chemicals when combined. In fact, that so-called "pool smell" is actually the scent of those chemicals, as Xing-Fang Li, an environmental chemistry professor who conducted research on the topic, told NPR. One of those chemicals—cyanogen chloride—is classified as a chemical warfare agent and can damage your heart and lungs. Other byproducts, called nitrosamines, can even cause cancer.

#2. You typically only breathe through one nostril at a time.

You might think that your nostrils share the workload when it comes to inhaling and exhaling. And while they do, it's not quite in the way that you might expect. You actually inhale and exhale through one nostril at a time, according to definitive research published in the journal Mayo Clinic Proceedings in 1977. Every few hours, the active nostril will take a break and the other one will take over until they ultimately switch back again. Put your finger under your nose and try it. Prepare to be amazed!

#3. Anxiety can make bad smells even worse.

Speaking of your nose, a 2013 study published in The Journal of Neuroscience examined the way certain emotions affect your sense of smell. After exposing subjects to anxiety-inducing images like car accidents and war, researchers found that neutral scents became unpleasant and bad smells became even worse.

#4. Men are more forgetful than women.

Numerous studies dedicated to comparing the memory abilities of men and women consistently prove that men are more forgetful than women. One 2015 study published in The Quarterly Journal of Experimental Psychology hypothesizes that this could be due to the varying brain structures of men and women—specifically, that the hippocampus (the part of the brain associated with memory) begins to decrease in volume faster in men than in women.

#5. Your pupils can hint at your Alzheimer's risk.

Of course, the telltale sign of Alzheimer's disease is memory loss, but dementia also manifests itself in your eyes. In a 2019 study published in the journal Neurobiology of Aging, researchers noted that the disease affects the locus coeruleus, a cluster of neurons in the brainstem responsible for pupillary responses, among other things. As a result, individuals with cognitive impairment who are at risk of developing Alzheimer's have greater pupil dilation while performing cognitive tasks.

#6. Eating eggs improves your reflexes.

If you want to be able to respond more quickly, you can start by having an omelette for breakfast. Eggs contain an amino acid called tyrosine, which the body synthesizes into norepinephrine and dopamine, compounds that increase energy and alertness and improve mood. In a 2014 study published in the journal Neuropsychologia, researchers even found that tyrosine enhances our response time and improves our intellectual performance, not unlike a medical stimulant like Ritalin or Modafinil.

#7. Your blood makes up nearly one-tenth of your total body weight.

When you look at how much you weigh on the scale, you probably think that number is compromised of fat and muscle. But did you know that your blood makes up 8 to 10 percent of your total body weight? Hematologist and oncologist Daniel Landau, MD, explained to Live Science that the average adult has anywhere from 1.2 to 1.5 gallons of blood flowing through their veins.

#8. But a newborn baby is born with barely any blood.

Naturally, newborn babies don't have nearly as much blood as adults do. So how much are they working with exactly? According to Landau, it's typically no more than 1 cup of blood for the average 5-to-8-pound newborn.

#9. And how much you weigh at birth can determine your allergy risk.

Though it's hard to tell whether a person will develop allergies, scientists have found that it is possible to determine an infant's likelihood of developing childhood food allergies or eczema based on one thing: their weight. In a 2019 meta-analysis from the University of Adelaide, researchers found that for each kg increase in birth weight, there was a 44 percent increase in the risk of childhood food allergies and a 17 percent increase in the risk of eczema.

#10. A tick bite can make you allergic to red meat.

There are plenty of food allergies out there, but few are the result of an insect bite. In a strange and growing trend, some people who get bitten by the Lone Star tick develop a sudden allergy to red meat, according to the American College of Allergy, Asthma, and Immunology. Beef, lamb, pork, and goat (which are technically classified as red meats) can make people with this allergy experience vomiting, cramps, difficulty breathing, and hives. In severe cases, it can cause the person to stop breathing entirely. For some people, the allergy fades over time, but for others, it's permanent.