Coronavirus disease (COVID-19): symptoms, causes and prevention (2023)

overview

What is coronavirus?

Coronaviruses are a family of viruses that can cause respiratory diseases in humans. They are called "corona" because of crown-like spikes on the surface of the virus. Severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and the common cold are examples of coronaviruses that cause disease in humans.

The new strain of the coronavirus - SARS-CoV-2 - was first reported in Wuhan, China in December 2019. Since then it has spread to all countries of the world.

Where do coronaviruses come from?

Coronaviruses are commonly found in bats, cats and camels. The viruses live in the animals but do not infect them. Sometimes these viruses then spread to different animal species. The viruses can change (mutate) when they are transmitted in other ways. Eventually, the virus can jump from animal species and start infecting humans. In the case of SARS-CoV-19, the first infected people are said to have contracted meat, fish and live animals in a food market.

How do you get COVID-19?

SARS-CoV-2, the virus that causes COVID-19, enters your body through your mouth, nose or eyes (directly through the airborne droplets or by transferring the virus from your hands to your face). It then travels to the back of your nasal passages and to the lining of the back of your throat. There it accumulates on cells, begins to multiply and migrates into the lung tissue. From there, the virus can spread to other body tissues.

How does the new coronavirus (SARS-CoV-2) spread from person to person?

Coronavirus is likely to spread:

• The virus spreads in respiratory droplets that are released into the air when an infected person coughs, sneezes, talks, sings, or breathes near you. You can become infected if you breathe in these droplets.
• You can also get the coronavirus from close contact (touching, shaking hands) with an infected person and then touching their face.

How long is a person with COVID-19 considered contagious?

If you have COVID-19 it can take several days for symptoms to develop - but you are contagious during this time. You are no longer contagious 10 days after the onset of your symptoms.

The best way to avoid spreading COVID-19 to others is:

• If possible, stay 6 feet away from others.
• Wear a cloth mask that covers your mouth and nose when around others.
• Wash your hands often. If soap is not available, use a hand sanitizer that contains at least 60% alcohol.
• Avoid crowded indoor spaces. Open the windows to let in as much outside air as possible.
• Stay self-isolating at home if you feel ill and have symptoms that could be COVID-19 or if you test positive for COVID-19.
• Clean and disinfect frequently touched surfaces.

Who is most at risk of getting COVID-19?

Some of the people at greatest risk of contracting COVID-19 include those who:

• Do you live in, or have recently traveled to, an area with persistent active spread.
• have had close contact with a person who has a laboratory-confirmed or suspected case of the COVID-19 virus. Close contact is defined as within 6 feet of an infected person for acumulativea total of 15 minutes or more over a 24-hour period.
• are over 60 years old and have pre-existing conditions or a weakened immune system.

How soon after being infected with SARS-CoV-2 will I develop COVID-19 symptoms?

The time between infection and the onset of symptoms (incubation period) can be two to 14 days. The average time before symptoms appear is five days. Symptom severity can range from very mild to severe. In about 80% of people, COVID-19 causes only mild symptoms, although this may change as variants emerge.

Can I get infected again if I recover from a case of COVID-19?

If you test positive for SARS-CoV-2 three months after your last positive test, this is considered reinfection. Before the Omicron variant, reinfection with SARS-CoV-2 was rare but possible.

Omicron (B.1.1.529) was first reported in South Africa in November 2021 and quickly spread around the world. With many mutations, omicron was able to evade the immune system and we had more reinfections than ever before.

Just as the virus that causes COVID-19 continues to domutate, Reinfection remains possible. Vaccination – including a booster – is the best protection against serious illness.

symptoms and causes

What are the symptoms of COVID-19?

COVID-19 symptoms vary from person to person. In fact, some infected individuals develop no symptoms (asymptomatic). Generally, people with COVID-19 report some of the following symptoms:

• Feveror chills.
• Cough.
• shortness of breath or difficulty breathing.
• Fatigue.
• muscle or body pain.
• Headache.
• New loss of taste or smell.
• Sore throat.
• congestion or runny nose.
• nausea or vomiting.
• Diarrhea.

Other symptoms are possible.

Symptoms can appear two to 14 days after exposure to the virus.Kinderhave similar but usually milder symptoms than adults. Older adults and people with serious underlying medical conditions are at higher risk for more serious complications from COVID-19.

Call 911 and see a doctor right away if you have these warning signs:

• difficulty breathing.
• Persistent chest pain or pressure.
• New confusion.
• Inability to wake up from sleep.
• Bluish lips or face.

This list does not include all possible symptoms. Contact your doctor if you think you may have coronavirus or are experiencing severe symptoms.

diagnosis and testing

How is the coronavirus diagnosed?

COVID-19 is diagnosed with a laboratory test. Your healthcare provider may take a sample of your saliva or swab your nose or throat to send it in for testing.

When should I get tested for the coronavirus (COVID-19)?

Call your doctor if you:

• Nausea with fever, cough or difficulty breathing.
• Have been in close contact with a person known or suspected to have COVID-19.

Your doctor will ask you questions about your symptoms and tell you if you need to be tested for COVID-19.

If I test positive for coronavirus, how long should I self-isolate?

According to current CDC recommendations, you should self-isolate until you have met both of the following criteria:

• It has been five days since your symptoms first appeared and your symptoms are improving.
• You have not had a fever for 24 hours and have not taken any antipyretic medication during this time.

When at home, isolate yourself in a separate room in your home if possible to limit interactions with other family members. If you cannot remain 100% isolated in a separate room, keep 6 feet away from others and wear a cloth mask, wash hands often, and disinfect high-touch surfaces and common areas.

You do not need to be retested after your period of self-isolation. But every case is unique, so follow your doctor's recommendations for testing.

If you have a compromised immune system or have had a severe case of COVID-19, the CDC's criteria don't apply to you. You may need to stay home for up to 20 days after your symptoms first appear. Talk to your doctor about your situation.

How long do I have to isolate if I've been with someone with COVID-19?

You should be quarantined for five days if:

• You are not fully vaccinated.
• It has been more than six months since your second dose of vaccine and you have not been boosted.

After this time, you should wear a well-fitting mask when you are with others for another five days. The CDC recommends testing on day five if possible. This quarantine period may vary depending on strain variant and test availability.

Is it possible to test negative for the coronavirus and still be infected with it?

Yes, it's possible. There are several reasons for “false negative” test results — it really means youagainHaving COVID-19 even though the test result says you don't have it.

Reasons for a false negative COVID-19 test result include:

• They were tested too early in the course of the disease.The virus has not multiplied in your body sufficiently for the test to detect it.
• Swab didn't get a good sample.You or the medical staff may not have swabbed deep enough into your nasal cavity to get a good sample. There could also be less likely handling errors and shipping errors.
• The test itself was not sensitive or specific enough to detect SARS-CoV-2, the virus that causes COVID-19.Sensitivity refers to the test's ability to detect the smallest amount of virus. Specificity refers to the test's ability to detect only the COVID-19 virus and not other similar viruses. Many different commercial and hospital laboratories have developed tests for SARS-CoV-2. All must meet standards, but there is always the possibility of "false negative" and "false positive" tests.

If you think you may have COVID-19, even if your test is negative, it's best to follow current CDC recommendations. Stay home for 10 days if you think you are sick (“social distancing”). Stay 6 feet away from others ("physical distancing") and wear a cloth mask. Contact your doctor if your symptoms worsen. Don't decide for yourself whether it's safe for you to be with others. Instead, contact your doctor if your symptoms improve.

management and treatment

What treatments do people who have COVID-19 receive?

Treatments for COVID-19 vary depending on the severity of your symptoms. Unless you are hospitalized or do not require supplemental oxygen, no specific antiviral or immunotherapy is recommended.

Depending on the severity of your COVID symptoms, you may need:

• Supplemental oxygen (via a tube inserted into the nostrils).
• Some people may benefit from an IV with monoclonal antibodies.
• Antiviral drugs can reduce the risk of hospitalization and death in certain patients with COVID-19.
• Mechanical ventilation (oxygen through a tube inserted into your windpipe). You will be given medication to keep you comfortable and sleepy as long as you are on oxygen on a ventilator.
• Extracorporeal membrane oxygenation (ECMO). You will continue to be treated while a machine pumps your blood out of your body. It takes over the function of the lungs and heart of your body.

Can vaccinated people still contract COVID-19?

Yes, it is possible to get COVID-19 even if you have been vaccinated. No vaccine is 100% effective. In fact, breakthrough cases (when someone tests positive more than two weeks after being fully vaccinated) are expected, especially if the SARS-CoV-2 virus mutates.

The vaccines greatly reduce your risk of infection but do not eliminate it. The risk of serious illness or death from breakthrough infection is very highlow.

How can I treat my symptoms at home?

If you have mild COVID-19 symptoms, you probably canManage your health at home. Follow these tips:

• if you have feverDrink plenty of fluids (water is best), get plenty of rest, and take acetaminophen (Tylenol®).
• if you have a coughLie on your side or sit up (do not lie on your back). Add a teaspoon of honey to your hot tea or hot water (do not give honey to children under 1 year old). Gargle with salt water. Call your doctor or pharmacist for advice on over-the-counter comfort care products such as cough suppressants and cough drops/lozenges. Arrange for a friend or family member to pick up any medication you need. You have to stay at home.
• If you're worried about your breathing, try to relax.Breathe in slowly through your nose and slowly out through pursed lips (like slowly blowing out a candle).
• If you have trouble breathing, call 911.

If you have a mild case of COVID-19, you should feel better in a few days to a week. If you think your symptoms are getting worse, contact your doctor.

prevention

How can I prevent getting COVID-19?

The best defense to avoid contracting COVID-19 is vaccination. You should also follow the same steps you would take to prevent getting other viruses such as B. the common cold or theFlu.

• wash your handsfor at least 20 seconds — especially before eating or preparing food, after using the toilet, after blowing your nose, and after being in contact with someone who has a cold.
• Wear a multi-layer cloth face mask that fits snugly to your face and covers your mouth, nose, and chin, as recommended by the CDC.
• Avoid touching your eyes, nose and mouth to prevent the spread of virus through your hands.
• When sneezing and coughing, cover your mouth and nose with a tissue or sneeze and cough into the crook of your arm. Throw the tissue in the trash. Wash your hands afterwards. Never cough or sneeze into your hands!
• Avoid close contact (within 6 feet) of anyone who has a cough, cold, or is ill. Stay home if you are sick.
• If you are prone to illness or have a weakened immune system, stay away from large crowds. Follow the advice of your health authorities, especially during outbreaks.
• Clean frequently used surfaces (like doorknobs and countertops) with a virus-killing disinfectant.
• Use hand sanitizers that contain at least 60% alcohol when soap and water are not available.
• Greet people with a friendly gesture instead of shaking hands.
• Get enough sleep, eat a healthy diet, drink plenty of fluids, and exercise when you can. These steps will strengthen your immune system and help you fight off infections more easily.

Should I wear a face mask?

Your healthcare provider can answer any questions you have about when to wear a face mask to slow transmission of COVID-19. In general, the CDC recommends wearing a face mask in the following situations:

• If you are in an area with a high level of COVID-19 in the community, wear a face mask in public.
• When you are ill but cannot avoid being with others.
• If you are caring for someone who has COVID-19.
• If you are at higher risk of developing a serious illness or live with someone who is.

A note from the Cleveland Clinic

We've come a long way since the first cases of COVID-19 were confirmed in the United States. We learned a lot about the virus and how to treat people who have it. We've also greatly increased our ability to test. They, our communities, have also made tremendous efforts to adapt.

The changes we've all made to stay safe and healthy can feel like a challenge. But please stay alert. We know it's not easy, but it's crucial. COVID-19 should not be taken lightly. While most people experience only mild symptoms, others develop serious lung, brain, and heart complications. There may also be other long-term effects that we don't know about yet.