Coronavirus: What Happens When You Get Infected?

There are many types of coronaviruses. Some give you the common cold. The new coronavirus responsible for the 2019-2020 pandemic causes an illness called COVID-19.

Here’s how it attacks your body.

Viruses infect your body by latching onto and entering healthy cells. Once inside, the invader makes copies of itself and multiplies throughout your body.

The coronavirus gains entry through your eyes, nose, or mouth. It then grabs onto your cells by latching its spikey surface proteins to receptors on normal cells, especially those in your lungs.

Specifically, the viral proteins bust into cells through the ACE2 receptors. Once inside, the coronavirus hijacks your healthy cells and takes over command. Eventually, they kill some of the healthy cells.

What Happens After an Infection

COVID-19, the illness caused by the coronavirus, starts in your respiratory tract. That’s the airway between your mouth, nose, throat, and lungs. It’s the same place that the common cold attacks. But COVID-19 can become more serious than the common cold because it is more likely to get deeper into your respiratory tract, including into your lungs. That’s because your lower airways have more ACE2 receptors.

When your body spots the virus, your immune system counterattacks. One sign of that is a fever. You might have a cough, too. That’s your body’s usual response to something that’s in the airways that shouldn’t be.

For most people, the symptoms end here. More than 8 in 10 cases are mild. But for some, the infection gets more severe.

Symptoms of Serious Cases

As the infection reaches your lower respiratory system, including the lungs, it can be hard for you to breathe. This is when more serious medical problems can crop up.

For example, many viral infections can cause pneumonia. This makes your airways swell and your lungs fill with fluid. In the most severe cases, this fluid in the lungs can lead to acute respiratory distress syndrome, or ARDS. People who get this condition are usually already in the hospital for the illness that caused it. ARDS makes it difficult or impossible to breathe.

As fluid collects in the lungs, they carry less oxygen to your blood. That means your blood may not supply your organs with enough oxygen to survive. This can cause organs like your kidneys, lungs, and liver to shut down and stop working.

Not everyone who has COVID-19 has these serious complications. And not everyone needs medical attention.But if your symptoms include trouble breathing, you need emergency help.

WebMD Medical Reference Reviewed by Neha Pathak, MD on March 20, 2020



Raina McIntyre, PhD, NHMRC Principal Research Fellow, Professor of Global Biosecurity, University of New South Wales, Sydney, Australia.

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