It happens every dang year. You spend the holidays having fun. Maybe you hit a party on New Years’ Eve. It’s cold outside, but you’re having a great time. Then one day you wake up, and your throat feels like you swallowed a porcupine. You get up to brush your teeth, and your stomach feels like it’s about to jump out of your mouth (or maybe a different orifice). The holidays are a bright light, but they cast a long, sneezy, uncomfortable shadow. That’s right, ladies and gents. It’s flu season.

You can get sick at any time of the year. Trust me. I’ve done it. The flu, though, that’s a seasonal illness. Even the name, influenza, speaks to that. It comes from the Italian influenza di freddo, meaning influence of the cold. The question, of course, is why. Why does the flu only come around to poison our new years and keep us in bed instead of opening gifts with family?

Research has given us insights into flu season and knowing them is half the battle. The other half is taking the right steps to fight back.

There are 5 reasons the flu arrives in winter and spreads so quickly.

1. CLOSE QUARTERS:

In winter, we stay inside. No one wants to go outside and freeze their skin off. Instead, folks stay bundled up in blankets. Some people make forts in their living rooms (if that’s not a winter tradition for you, I recommend adding it to the catalog). When you’re inside, all your germs are there with you. With everyone huddled together for warmth, it’s easy for the flu to move from one person to the next. Even worse, the cold can lead to stuffy noses or dry throats, which make it even harder to identify flu symptoms.

2. BABY, IT’S DARK OUTSIDE:

The sun sets early on these frozen lands. Without its light, our bodies don’t produce the amount of vitamin D we need. Vitamin D combats the potential inflammation left behind by white blood cells. More than that, it boosts the growth of proteins your immune system needs to fight off illness. Without those vitamins, your body just doesn't have enough resources to fight back.

3. GETTING STUFFED:

The cold clogs your nose. That might sound obvious, but it goes deeper than you think. It’s not just boogers that seal up your nasal cavity. Your body closes those tubes to conserve warmth and prevent hot air from seeping out. Without air to clear them out, our nostrils become a comfortable place for all sorts of nasty things to grow (Like the flu!).

4. WHAT IS INFLUENZA?:

That’s a hard question to answer. The influenza virus morphs and adapts much faster than other illnesses. That is why there are new vaccine updates for the flu every year. It’s also the reason why your body’s immune system doesn’t build up residual defenses against the flu. Instead, your body has to create new systems to protect itself every single year. It’s like your body has spent all year studying French literature, and then in winter the test is on Shakespeare.

5. THE PERFECT CLIMATE:

This is the big one. According to studies by Dr. Peter Palese, the most significant factors in the spread of influenza are temperature and humidity. Palese discovered that the flu is most stable at temperatures at and below 41 degrees Fahrenheit, and spreads most easily in humidity at or below 20%. We often think moisture leads to illness, but with influenza this is not the case. The lack of water in the air makes the tiny flu particles light enough to float. That means the sickness can be transmitted just by breathing near someone with the flu. Those variables make the cold, dry air of winter the ideal breeding ground for the flu.

Thank God For Guinea Pigs

A little bit of history, if you're interested. For decades, while the flu was running rampant, there was no way to run useful studies. It was illegal to test the illness on humans, and there were no animals affected by the influenza virus that affects people. It wasn’t until Palese found a journal from 1919 that discussed the deaths of local guinea pigs during flu epidemics that research began.

When it comes to preventing the flu: Vaccines and hygiene are great ways to get ahead of the game, but vaccines aren’t for everyone and hygiene isn’t foolproof. Now you’re wondering how to prevent the flu from coming for you. Don’t worry. We’ve got your back.

1. GET COMFORTABLE:

So, it’s winter time. You’re going to be at home hiding from the biting winds no matter what. Instead of using that time to binge watch Frasier (or a show people actually watch), try getting a good night’s sleep. Without a good night’s sleep, T cells can diminish, and inflammatory cytokines can increase. Those two factors working together can reduce your immune system’s ability to prevent getting sick. Eight hours of uninterrupted sleep every night is an easy path to an immune system boost.

2. TURN UP THE HUMIDITY:

I just told you that the flu spreads best in dry air, so why not increase the moisture? According to Tyler Koep, a Ph.D. student at the Mayo Graduate Program, running a humidifier in a school can reduce instances of the flu by 30%. If that’s all it takes to make that kind of impact on a school, where dirty kids are spreading diseases constantly, imagine what it could do in your home.

3. GET YOUR BLOOD PUMPING:

Your body needs white blood cells to fight against illness, and those blood cells need to move fast. The best way to speed up that process is with exercise. Exercise gets your blood moving faster, and that allows the right cells to get to the right place at the right time. There are even some studies that indicate that with exercise, your body creates more cells that promote immunity by fighting both bacteria and viruses.

4. FUEL THE MACHINE:

Remember before, when we were talking about vitamins, and how winter can get in the way of your body producing the ones you need? Well, you can change that by getting the vitamins you need from the world around you. Eating foods that are high in vitamin content like fatty fish, fruits, and nuts, will give your body the resources it needs to fight back against the flu and any other illness dumb enough to step into the ring with your white blood cells.

5. YOUR SECRET WEAPON:

Now, it’s clear at this point that you want to get your immune system humming at full power. The thing is, you might be surprised by where most of your immune system is. Studies show that 80% of your immune system lives in your stomach. To get the most out of your immune system, you have to keep a steady balance between the different types of bacteria that live inside of you. Diet and exercise help with that, but there’s an even better way. Probiotics are designed to promote digestive health and immune function. Not only will this make your stomach work better it will make you feel better overall, since 95% of serotonin, the feel-good hormone, lives in your belly.

So now you’re ready to face the world, and no flu is getting in your way. Exercise, eat healthy, take probiotics, and maybe run a humidifier every once in a while. Those four easy steps can keep you away from the sickbed and grandma’s chicken soup (as tasty as it is).

*These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.