We're officially months deep into flu season! And, even if you haven't felt that telltale pounding in your head, crushing fatigue and all-over body ache that comes with the flu, you probably know at least someone who's had a bad time this year thanks to the flu virus.

That's because the incidence of the flu has been growing year over year, according to the Centers for Disease Control and Prevention. The CDC's weekly influenza report notes that every region of the US currently has more people than usual sick with the flu – and that the flu is "widespread" across Puerto Rico and 48 states.

But what really happens in your body when you have the flu – aside from feeling pretty awful? Read on to find out – and why some common flu "treatments" don't actually work.

First things first: Influenza is a virus – not a bacteria like many people think. It can be transmitted by touch contact but, more often, it's transmitted through the air (thanks in part to folks who don't cover their mouth when they cough or sneeze).

The influenza virus infects the specialized epithelial tissue that lines your respiratory tract (like your nose, throat and airways). Once the virus enters your epithelial cells, it's able to "hijack" the machinery your cells usually use to create new proteins, and tricks them into creating more viral particles instead.

Then your cells release the newly created viruses – so they go on to infect more cells, and create even more viruses. Soon, that single virus turns into a major infection and, well, you get sick.

Thankfully, your immune system doesn't just chill while the flu virus works its way through your respiratory tract – it starts to fight back. Special immune cells, called T-cells, circulate through your body looking for infection.

When they find out – like infected cells or flu viruses – they put your immune system on high alert. Other immune cells, called B-cells, rush in to start engulfing and destroying the viral particles, working to clear the infection from your system.

That immune response isn't without its downsides, though. Once your immune system goes on alert, it releases chemicals, called cytokines, that trigger inflammation. And it's actually the immune response that's partly responsible for some of the most annoying or dangerous symptoms of the flu, like your stuffy nose or fever.

In severe cases, the inflammation from your immune response can actually damage lung tissue and making breathing more difficult – which is why the flu can be so dangerous for people who already have breathing problems.

However, a strong and healthy immune system can clear the flu within a matter of days. Then the inflammation goes down, and you slowly start to return to normal.

So, now you know how the flu turns your respiratory tract into a hotbed of infection – and makes you want to sleep for a whole week. So let's address some common myths surrounding flu season.

Myth #1: Antibiotics Help with the Flu

Not true! The flu is a virus – not a bacteria – so antibiotics have no effect. Consult your doctor for the best way to handle the flu, but don't be surprised if she doesn't prescribe antibiotics!

Myth #2: The Flu Shot Doesn't Really Work

This common argument against getting the shot is bunk. Scientists create the flu vaccine based on the influenza strains they think will be most common in the next flu season. They're not always 100 percent correct, so some years' vaccines are more effective than others, but the shots do protect you. This year's vaccine is 47 percent effective, the CDC reported last week.

Myth #3: Chicken Soup Treats the Flu

Sorry, but even your mom's tastiest chicken noodle won't stop the flu virus, Harvard Medical School explains. However, chicken soup can help you stay hydrated and soothe a sore throat, which might make you feel better as you recover.