Coronavirus: What Happens When You Get Infected?

Medically Reviewed by Dan Brennan, MD on December 29, 2022
3 min read

There are many types of coronaviruses. Some give you the common cold. The coronavirus behind the 2019-2022 pandemic causes an illness called COVID-19.

virus infects your body by entering healthy cells. There, the invader makes copies of itself and multiplies throughout your body.

The coronavirus latches its spiky surface proteins to receptors on healthy cells, especially those in your lungs.

Specifically, the viral proteins bust into cells through ACE2 receptors. Once inside, the coronavirus hijacks healthy cells and takes command. Eventually, it kills some of the healthy cells. There is some evidence, though, that the Omicron variant doesn’t attack lung tissue as much as other variants did.

COVID-19, the illness caused by the coronavirus, starts with droplets from an infected person’s cough, sneeze, or breath. They could be in the air or on a surface that you touch before touching your eyes, nose, or mouth. That gives the virus a passage to the mucous membranes in your throat. Within 2 to 14 days, your immune system may respond with symptoms including:

  • Fever
  • A cough
  • Shortness of breath or trouble breathing
  • Fatigue
  • Chills, sometimes with shaking
  • Body aches
  • Headache
  • A sore throat
  • Congestion or a runny nose
  • Loss of taste
  • Loss of smell
  • Nausea or vomiting
  • Diarrhea

The virus moves down your respiratory tract. That’s the airway that includes your mouth, nose, throat, and lungs. Your lower airways have more ACE2 receptors than the rest of your respiratory tract. So COVID-19 is more likely to go deeper than viruses like the common cold.

Your lungs might become inflamed, making it tough for you to breathe. This can lead to pneumonia, an infection of the tiny air sacs (called alveoli) inside your lungs where your blood exchanges oxygen and carbon dioxide.

If your doctor does a CT scan of your chest, they’ll probably see shadows or patchy areas called “ground-glass opacity.”

For most people, the symptoms end with a cough and a fever. More than 8 in 10 cases are mild. But for some, the infection gets more severe. About 5 to 8 days after symptoms begin, they have shortness of breath (known as dyspnea). Acute respiratory distress syndrome (ARDS) begins a few days later.

ARDS can cause rapid breathing, a fast heart rate, dizziness, and sweating. It damages the tissues and blood vessels in your alveoli, causing debris to collect inside them. This makes it harder or even impossible for you to breathe.

Many people who get ARDS need help breathing from a machine called a ventilator.

As fluid collects in your 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 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 care. Some research even suggests the Omicron variant may not be as severe in the lungs as other variants. But if your symptoms include trouble breathing, get help right away.

Some people also have symptoms including:

  • Pinkeye
  • Rashes
  • Liver problems or damage
  • Heart problems
  • Kidney damage
  • Dangerous blood clots, including in their legs, lungs, and arteries. Some clots may cause a stroke.

Researchers are looking into reports of mouth sores and skin rashes, including reddish-purple spots on fingers or toes.

In general, children don't get as sick with coronavirus as adults do, but they can be infected and it can also be deadly for them. Some children and teens have been admitted to the hospital with an inflammatory syndrome that may be linked to the coronavirus. Symptoms include a fever, rash, belly pain, vomiting, diarrhea, and heart problems. The syndrome, now being referred to as multisystem inflammatory syndrome in children (MIS-C), is similar to toxic shock or to Kawasaki disease, a condition in children that causes inflammation in blood vessels. We’re still learning about these cases.

The long-term effects of COVID-19 on your body are still unclear. Some patients have become what is being called "long-haulers" where they suffer symptoms for weeks and even months.