1. Smegma No one really wants to talk about smegma, a naturally-occurring lubricant that is comprised of dead skin and oils. In women, it occurs in the folds of the labia and clitoris. In men, it is seen in the inner cavity of the foreskin (which is why most American men don't have it). Smegma also coats the skin against microbial and bacterial invaders. It tends to be clear and odorless when clean, but sometimes builds up and becomes opaque and smelly, which is why this helpful secretion has a few bad names. In fact, letting it build up can be harmful as the waste it creates can irritate your genitals. If you clean your genitals with water and mild soap on a regular basis, smegma can be your very misunderstood, icky, and unmentionable, friend. 2. Mucus Without mucus, you'd likely be dead. As Dr. Michael M. Johns III explains, "It is the oil in the engine. Without mucus, the engine seizes." Mucus lubricates your airways so you can breathe properly, and also protects your gastrointestinal tract so you can digest your food. The stringy, sticky stuff also works to trap bacteria, dust, pollen, and other unmentionables you breathe in that shouldn't be in your lungs. It even has antibodies and enzymes that kill bacteria and viruses to prevent you from getting sick. A healthy body produces a half a gallon of mucus every day, with your nose pushing out a new batch every 20 minutes. Most of it is swallowed before you even notice. However, when your body is irritated by an allergen or a virus, you start producing mucus of a thinner consistency to force out the offending intruder, which is why you notice having a runny nose. Sometimes, however, you might instead get congested with thicker mucus that doesn't slide down your throat. This tends to be a result of dehydration, a common side effect of sickness, and why your doctor always tells you to hydrate when you don't feel well 3. Bacteria Some strains of bacteria can cause nasty infections, but you'd be nothing without it as a whole. In fact, your body contains equal parts microbial cells (bacteria, viruses, and other microbes) and human cells, meaning your just as much non-human as you are a person! While people are starting to accept that not all bacteria are harmful, hence the proliferation of probiotics, most still overwhelmingly associate bacteria with disease. But the reality is that fewer than 15% of the bacteria in our bodies can cause illness, and the other 85% helps us survive or, at very least, doesn't hurt us. Good bacteria helps us break down and digest our food, boosts our immune system, synthesizes vitamins essential to our survival, and keeps vaginas free from a number of illnesses, including yeast infections 4. Vomit There's no denying that vomiting isn't pleasant, but the ejection of your stomach's contents can be a very, very good thing—it has saved the lives of many poison and food-borne illnesses victims over the millennia. Unfortunately, our bodies don't always know when they are protecting us from something dangerous, when they're just responding to a mild flu or the hormones that cause morning sickness, so not all instances of vomiting are helpful. While it may be uncomfortable and unpleasant, for the most part it's also harmless, which is why the body seems to have adapted a "better safe than sorry" policy when it comes to triggers. Vomiting can cause dehydration and can sometimes be a warning a more serious illnesses, so if you can't hold liquid down or if you have been vomiting repeatedly for more than 24 hours, you should probably see a doctor. But if you occasionally have to throw up after drinking too much or eating something sketchy, don't be upset about vomiting—be glad that your body is trying to protect you! 5. Pus When you're squeezing a pimple, the sight of pus is always a bit unnerving and nauseating, but it is an important part of our immune system. Pus is made mostly from white blood cells that have flooded the area to fight the bacteria or fungus causing the infection. While most people take its appearance in a wound as a bad sign as it means the wound is infected, it also means your body is healthy and fighting the infection naturally. Of course, if you have a bad infection with a lot of pus, it's a good idea to help your body fight the infection by cleaning the wound regularly and seeing a doctor to get antibiotics rather than letting your white blood cells do all the work. 6. Earwax North Americans spend over $60 million on home ear cleaning products, and 12 million people visit the doctor every year to have their earwax removed professionally. Howeve, the ear is designed to be a self-cleaning orifice, and if people just let it be, they wouldn't have so much ear wax build up in the first place. Earwax moisturizes the ear canal and protects your ear drums from dirt, dead skin cells and bacteria. The last third of the ear canal is where you wax is produced, and wax travels towards the ear opening when left alone. Using a Q-Tip often pushes the wax past where it's produced and traps it so it can no longer escape. This can lead to pain and serious hearing problems that will only be relieved when you or your doctor manages to eject all that built up earwax from the ear canal. 7. Water Blisters These weird skin bubbles, made from serum or plasma, protect injured, deeper layers of skin. While blisters are painful and cumbersome, it's better not to pop them as they protect the skin from infection and help it heal. The liquid inside the blister will eventually reabsorb into the body. Note that blood blisters are different, as they are generally not caused by friction or burns and are, obviously, filled with blood. In rare cases, large water blisters may need to be drained or may get infected, and in these cases you should probably see a doctor. Also, see a doctor if you have multiple blisters all over your body that have not been caused by burns or friction, as this can be a sign of illness. 8. Sweat The $19 billion dollar antiperspirant and deodorant industry is a pretty big indication that most people don't like dripping with sweat all day. But sweat glands evolved for a reason, and that is to keep us cool. Human body temperature is 98.6 degrees Fahrenheit, but both working out and warm weather increases it. Sweat helps regulate the body by cooling us down as it evaporates, which is also why places with high humidity and no wind seem so much warmer than places with low humidity and high winds. While many people associate sweat with stench, sweat itself is just water with a tiny amount of sugar, salt and other minerals—in other words, it doesn't actually stink. The reason so many people stink after sweating is that sweat mixes with bacteria on your skin and causes a reaction. Unsurprisingly, areas like armpits tend to have more bacteria, which is why they tend to be noticeably rank when you sweat a lot. Source
