Health Library

What Is COVID-19?

At the end of 2019, a new type of coronavirus, called SARS-CoV-2, began making people sick with flu-like symptoms. The illness it causes is called coronavirus disease-19 — COVID-19, for short. The virus spreads easily and has affected people all over the world.

Safe and effective COVID-19 vaccines and booster shots are available for adults and all children ages 6 months and older. Everyone who is eligible should get these as soon as possible.

What Is a Pandemic?

When a disease affects many people in a community or other limited area, it’s called an epidemic. If the disease spreads to many countries or around the world, it’s called a pandemic.

The worldwide spread of COVID-19 is a pandemic. At times, many more people have gotten infected than at other times. These are called surges or waves. The virus spreads easily, so surges are most likely when people gather and aren’t wearing masks or aren’t vaccinated. They’re also more likely if the virus changes to a more contagious form.

Sometimes a disease can become endemic. This means the disease is always around in a certain community or limited area, but it doesn’t affect people in surges or waves. When a disease is endemic, it spreads in a stable and predictable way. The flu and the common cold are both endemic infections. It’s too early to tell if or when COVID-19 will become endemic.

What Are the Signs & Symptoms of Coronavirus (COVID-19)?

Infection can cause a range of symptoms. Most common are fever, cough, trouble breathing, and gastrointestinal problems like bellyache, nausea, vomiting, and diarrhea. Other complaints include headaches, muscle aches, loss of taste and smell, and cold symptoms. The virus can be more serious in some people. And some people have no symptoms at all.

What Is MIS-C?

Some kids get symptoms caused by inflammation throughout the body a few weeks after they were infected with the virus. It can affect many different body systems, including the lungs, heart, brain, kidneys, blood vessels, skin, eyes, and gastrointestinal system. This is called multisystem inflammatory syndrome in children (MIS-C). MIS-C is a serious condition that can lead to organ damage if not treated quickly. But it’s very rare and most kids fully recover after getting medical care.

What Is Long COVID?

Rarely, some people have symptoms that last for a long time (usually more than a month), a condition known as long (or long-haul) COVID. Sometimes these symptoms begin while a person is still sick, but they also can start after someone recovered or after they had an infection with no symptoms. These symptoms can include tiredness, headache, trouble sleeping, trouble breathing, trouble concentrating (“brain fog”), muscle and joint pain, heart palpitations, and changes in their sense of taste and/or sense of smell.

How Does Coronavirus (COVID-19) Spread?

People can catch COVID-19 from others who have the virus even if they have no symptoms. This happens when an infected person breathes, talks, sneezes, or coughs, sending tiny droplets into the air. These can land in the nose, mouth, or eyes of someone nearby, or be breathed in. Some of the tiniest droplets, called aerosols, can linger in the air for minutes to hours and travel on air currents. But it seems that the risk of spread is highest when people are less than 6 feet apart, when they spend a lot of time together, when they gather indoors, and when the indoor space is poorly ventilated.

People also might get infected if they touch an infected droplet on a surface and then touch their own nose, mouth, or eyes. But this type of spread is a lot less common.

Experts are looking at how the virus spreads and stays in the air, and if it can spread through stool (poop). They’re also looking at whether an infected pregnant woman can pass the virus to her baby, which seems to be possible but rare.

Masks are no longer required in most public places in the U.S., but it’s still a good idea for people to wear them, especially when indoors or in crowded outdoor settings, if:

• They live in an area with a high rate of COVID-19 infections.
• They have weak immune systems or some types of medical conditions.
• They take public transportation.

Mask guidelines can change based on the rates of COVID-19 in a community at any given time. For now, people should always wear masks if they have COVID-19 or if they have been exposed to it. For more information about masks, visit the CDC’s guide.

Is Coronavirus (COVID-19) Dangerous to Children?

Fewer infections have been reported in children, and they also usually seem to have a milder illness. But some children with more serious symptoms (such as those with MIS-C) need treatment in a hospital. Some kids have died from COVID-19.

COVID-19 can sometimes lead to myocarditis, an inflammation of the heart muscle. In kids, the most common symptoms include tiredness, trouble breathing, chest pain, or belly pain. Most children recover fully from myocarditis, but sometimes it can be more serious and cause lasting heart damage.

Doctors have noticed that more kids than usual have been diagnosed with diabetes during the pandemic, especially after being sick with COVID-19. The reasons for this are not yet clear, but studies are underway to figure out why.

How Is Coronavirus (COVID-19) Treated?

Most people with a mild illness, including children, don’t need any specific treatment. They get better with rest, fluids, and fever-reducing medicine.

A very few kids who are at higher risk for severe COVID-19 can get certain medicines, such as antiviral drugs or monoclonal antibodies, to keep them from getting very sick and needing hospital care.

Some people who get very sick from COVID-19 will need hospital care, possibly in the ICU. Doctors can closely watch them, give oxygen or IV fluids if needed, and treat any problems. Rarely, they will also give medicines such as antiviral drugs, monoclonal antibodies, or steroids. Someone who needs extra help to breathe will be connected to a breathing machine (a ventilator).

What Should I Do if My Child Has Symptoms of Coronavirus (COVID-19)?

Call your doctor if your child has symptoms of COVID-19 or MIS-C, or just isn’t feeling well. Tell the doctor if your child has been near someone with COVID-19, or lived in or traveled to an area where lots of people have the coronavirus. The doctor can decide whether your child:

• should get tested for the infection
• can be treated at home
• should come in for a visit
• can have a video or telehealth visit

Get care right away if your child:

• has trouble breathing
• has severe belly pain
• has pain or pressure in the chest
• is confused or not making sense
• has trouble staying awake
• looks bluish in the lips or face

These symptoms can be warning signs of serious illness.

What Else Should I Know?

To help prevent the spread of germs, it’s always a good idea to:

• Wash hands well and often. Wash for at least 20 seconds with soap and water or use hand sanitizer with at least 60% alcohol.
• Avoid people who appear sick.
• Clean things that get touched a lot (like doorknobs, counters, phones, etc.).

Where Can I Learn More About Coronavirus (COVID-19)?

Check the CDC and WHO websites for up-to-date information.