14 bizarre bodily functions you just cannot control

The human body really is amazing in so many ways. It can jump and run, dance and spin, and that’s just the physical side. But so many of the body’s awe-inspiring moves happen without assistance or even our knowledge. No matter how hard you try, these are the bodily functions that you just can’t control.

This sounds like it hurts, and in some cases it does – the constant tearing of muscle tissue may be why you feel a bit sore after a workout. But, it’s also the key to developing more muscle strength. “Placing stress on muscle tissue, such as when weight training, causes tiny, microscopic tears in the muscle fibres, which are actually needed for muscle growth,” says Erin Palinski-Wade, a registered dietitian and author of 2 Day Diabetes Diet. “When at rest, the body works to repair and rebuild these torn fibres by fusing muscle fibres together to form myofibrils, or new muscle protein strands, that then increase in number and thickness to create growth of the muscle itself.” Still, you should listen to your body and not overdo it when exercising to prevent injury.

Here are 5 daily habits that keep your muscles strong.

If you have long hair, you might worry when you see so much of it clogging up your shower drain – but it’s totally natural for us to shed. “Most of us lose up to 100 hairs from our scalp every day, which is normal,” says family physician Jennifer Caudle, DO, an assistant professor at Rowan University School of Osteopathic Medicine. But according to the American Academy of Dermatology, excessive hair shedding, which may temporarily occur from physical or emotional stress, is different from hair loss, in which the hair actually stops growing. If you think you have excessive hair loss, see your doctor.

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Your nails help protect the tissues of your fingers and toes. They grow faster the more you use them – and they grow faster on your dominant hand. “Fingernails grow about 2.5 millimetres each month, and it can take about three to six months to completely replace a nail,” says Dr Caudle. Interestingly, fingernails grow faster during the day and in the summer, leading some researchers to believe the rate of nail growth is also linked with better circulation.

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We think of gastrointestinal gas as gross and releasing it as rude, but it’s actually a normal bodily function. “Everyone has gas, and most people pass gas 13 to 21 times a day,” Dr Caudle says. According to Johns Hopkins Medicine, most people make about 475ml to nearly two litres of gas a day. It has to be let out somehow! “Gas in your stomach, released with burping, is primarily caused by swallowing air when we eat or drink,” Dr Caudle says. “Gas forms in the large intestine when bacteria ferment undigested food from the small intestine. Bacteria consume some of that gas, but the remaining is released by passing gas from the anus.” Some foods may produce more gas than others, and acid reflux and other medical conditions can also cause increased burping. Most gas is odourless, but farts can contain sulphur that gives them an unpleasant scent.

Discover 7 things your burps can reveal about your health.

Chalk this one up to evolution – if we had fur, goosebumps would serve a clear purpose. “Goosebumps happen involuntarily and are caused when a small muscle at the bottom of each hair follicle contracts, causing the hair to stand up. In animals this may actually form a layer of insulation,” Dr Caudle says. “They can occur due to cold air or also happen when we experience strong emotions such as shock, fear, anxiety, or even being inspired.” Such situations trigger a flight-or-fight response in animals, so they raise their hair to create a bigger appearance in an attempt to scare off their enemy.

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Why we yawn is one of the biggest unsolved mysteries of the human body. But there are some theories. “Yawning is a natural reflex of the body that allows more oxygen to be inhaled,” says Mehwish Awan Khan, MD, family medicine physician. In this way, stretching out with a big yawn could be a way to wake us up. Another theory, supported by research in Physiology & Behavior, is that yawning has an effect on brain thermoregulation, and helps to cool it down. Whatever the cause, one study in Evolutionary Psychology suggests you can try nasal breathing to stop yawns from continually happening.

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While saliva in the wrong place at the wrong time can be downright disgusting, it’s crucial for oral health and digestion. “The purpose of saliva is to moisten food to make it easier to swallow,” Dr Khan says. In addition, saliva “assists with taste and improves mouth hygiene by preventing mouth infections and tooth decay,” Dr Caudle says.

But what exactly is saliva? “It mostly consists of water, but has other chemicals and enzymes as well,” Dr Caudle says. “Saliva is produced by the salivary glands, which secrete about one to two litres of saliva every day.” Having loads of spit is actually preferable to a dry mouth, which can lead to bad breath and bacterial infection.

Watch out for these 12 common teeth-cleaning mistakes that make dentists cringe.

Although too much oil can be a bad thing, you need some of the bodily fluid called sebum to keep your skin moisturised and healthy. “We are a nation obsessed with that ‘squeaky clean feeling’ and antibacterial soap,” says Whitney Bowe, MD, a board-certified dermatologist and author of The Beauty of Dirty Skin. “If your skin feels stripped or squeaky clean after you cleanse, you are harming your skin’s healthy barrier and drying it out.”

Our sebaceous glands produce the oily substance called sebum to lubricate and waterproof our skin, deliver important nutrients, and protect our skin against environmental pollutants and free radical damage, she says. “Our skin’s natural barrier is critical to our skin’s health, so use a gentle, pH-balanced cleanser when washing and refrain from scrubbing or using harsh products,” Dr Bowe says. “If we over-cleanse and strip away too much of our skin’s healthy oils, our skin tends to over-correct and pumps out even more oil, which can contribute to breakouts and other skin issues.”

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It’s true – you’re living among piles of dead human skin cells. “Over the course of a day, we shed almost a million dead skin cells, approximately 30,000 to 40,000 every hour of any given day,” Dr Bowe says. “Our stratum corneum [outermost layer of skin] consists of about 15 to 20 layers of dead skin cells, which shed to allow new living cells to push up from beneath them.” This organic material is a major contributor to household dust – which some people find gross to contemplate. It’s important to exfoliate dead skin gently, so it doesn’t clog pores.