Yet even though this disease affects hundreds of millions of people each year, it still doesn't have a cure.

But of course, we're still looking.

So in the meantime, keep those cop drops handy and, of course, keep on washing your hands.

Nobody likes to have a cold, but actually there's many different viruses that can cause the common cold.

My name is Ellen Fox Hman.

I'm a faculty member at Yale University School of Medicine, and I have a research lab where we study respiratory viruses.

Ellen's right.

There are more than 200 different viruses that have been known to cause the common cold, but for now we'll be focusing on the biggest group, one that's responsible for over half of all colds.

Called human rhinoviruses.

These respiratory viruses are only 15 to 30 nanometers in diameter, making them some of the smallest viruses out there.

And it's partly thanks to their genetic makeup that they're so good at replicating.

Their genome is a very relatively small piece of RNA that Onley encodes about 10 different genes, but that is a very powerful tiny little particle.

And it only needs those 10 genes because it uses a lot of the machinery that's already there inside your cells to make more copies of itself.

So it's really actually incredible that with on Lee, this very small piece of RNA, the virus is able Thio do what it does and caused millions of illnesses in our country every year.

That's because human rhinoviruses, like most other respiratory viruses, travel via nasal secretions through the air like a sneeze or a surface called a phone Might, ah, phone might could be something like a keyboard or a door knob that could help spread the virus from one person to another.

From there, all it takes is for a contaminated hand to touch one of the bodies.

Mucous membranes like the eyes, nose or mouth and bam!

The viruses gained entry.

Where this virus likes to grow is in the cells that form the lining of the airway, and it gets into those cells and it just takes over and starts making more copies and then putting out those copies.

That's why you feel like your throat is so irritated and that's why you have the like.

Running, he knows, is because your body detects this irritation.

This problem where some of the cells are getting killed or some of the cells are getting taken over soon after.

Infection, coughing, sneezing, headaches, mild fever and body aches can follow.

And these symptoms may easily be confused with those of the flu.

But unlike the flu, where symptoms start quite suddenly, it could take a couple of days for cold symptoms to fully develop.

And they usually last anywhere from 7 to 14 days.

Now, as annoying as those average symptoms, maybe there's not much we can do about them.

While some therapies can help treat the symptoms, there's no cure all for the common cold.

Basically, you're just stuck with it for a good week or so.

And for the majority of people, this may just mean a couple of days and bet.

But for others, a rhinovirus infection could be quite serious.

For example, for people with asthma, especially kids with asthma.

Ah, huge amount of their asthma attacks are caused by rhinovirus or for people with chronic lung disease.

Ah, lot of the percentage of the time that they get in the hospital because their disease got worse is because of rhinovirus.

And for those people, it would be very beneficial to have a great antiviral drug.

But it seems we're still a ways out from finding one.

Ever since human rhinoviruses were first discovered in the 19 fifties, we've been trying to create vaccines and antivirals, but we just haven't had much success.

It's been a hard because there are many, many different variants of rhinovirus, and there's always new ones arising.

That means that the virus would be pretty adept to evade a vaccine or an antiviral drug.

But while we haven't been able to crack the cold just yet, its prevalence proves just how important preventative measures are.

So keep washing your hands.

Avoid touching your face and clean surfaces around you often.

Since it looks like the common cold will be with us for the long haul, try to figure out these natural defenses and how they work and just promote those defenses more often.

Do what you need to dio thio.