Apr 27 , 2020
As we continually learn more about coronavirus and COVID-19, it can help to reacquaint yourself with some basic information. For example, understanding how the virus spreads reinforces the importance of social distancing and other health-promoting behaviors. Knowing how long the virus survives on surfaces can guide how you clean your home and handle deliveries. And reviewing the common symptoms of COVID-19 can help you know if it's time to self-isolate.
What is coronavirus?
Coronaviruses are an extremely common cause of colds and other upper respiratory infections.
What is COVID-19?
COVID-19, short for "coronavirus disease 2019," is the official name given by the World Health Organization to the disease caused by this newly identified coronavirus.
How many people have COVID-19?
The numbers are changing rapidly.
It has spread so rapidly and to so many countries that the World Health Organization has declared it a pandemic (a term indicating that it has affected a large population, region, country, or continent).
Do adults younger than 65 who are otherwise healthy need to worry about COVID-19?
Yes, they do. Though people younger than 65 are much less likely to die from COVID-19, they can get sick enough from the disease to require hospitalization. According to a report published in the CDC's Morbidity and Mortality Weekly Report (MMWR) in late March, nearly 40% of people hospitalized for COVID-19 between mid-February and mid-March were between the ages of 20 and 54. Drilling further down by age, MMWR reported that 20% of hospitalized patients and 12% of COVID-19 patients in ICUs were between the ages of 20 and 44.
People of any age should take preventive health measures like frequent hand washing, physical distancing, and wearing a mask when going out in public, to help protect themselves and to reduce the chances of spreading the infection to others.
What are the symptoms of COVID-19?
Some people infected with the virus have no symptoms. When the virus does cause symptoms, common ones include fever, dry cough, fatigue, loss of appetite, loss of smell, and body ache. In some people, COVID-19 causes more severe symptoms like high fever, severe cough, and shortness of breath, which often indicates pneumonia.
People with COVID-19 are also experiencing neurological symptoms, gastrointestinal (GI) symptoms, or both. These may occur with or without respiratory symptoms.
For example, COVID-19 affects brain function in some people. Specific neurological symptoms seen in people with COVID-19 include loss of smell, inability to taste, muscle weakness, tingling or numbness in the hands and feet, dizziness, confusion, delirium, seizures, and stroke.
In addition, some people have gastrointestinal (GI) symptoms, such as loss of appetite, nausea, vomiting, diarrhea, and abdominal pain or discomfort associated with COVID-19. These symptoms might start before other symptoms such as fever, body ache, and cough. The virus that causes COVID-19 has also been detected in stool, which reinforces the importance of hand washing after every visit to the bathroom and regularly disinfecting bathroom fixtures.
Can COVID-19 symptoms worsen rapidly after several days of illness?
Common symptoms of COVID-19 include fever, dry cough, fatigue, loss of appetite, loss of smell, and body ache. In some people, COVID-19 causes more severe symptoms like high fever, severe cough, and shortness of breath, which often indicates pneumonia.
A person may have mild symptoms for about one week, then worsen rapidly. Let your doctor know if your symptoms quickly worsen over a short period of time. Also call the doctor right away if you or a loved one with COVID-19 experience any of the following emergency symptoms: trouble breathing, persistent pain or pressure in the chest, confusion or inability to arouse the person, or bluish lips or face.
One of the symptoms of COVID-19 is shortness of breath. What does that mean?
Shortness of breath refers to unexpectedly feeling out of breath, or winded. But when should you worry about shortness of breath? There are many examples of temporary shortness of breath that are not worrisome. For example, if you feel very anxious, it's common to get short of breath and then it goes away when you calm down.
However, if you find that you are ever breathing harder or having trouble getting air each time you exert yourself, you always need to call your doctor. That was true before we had the recent outbreak of COVID-19, and it will still be true after it is over.
Meanwhile, it's important to remember that if shortness of breath is your only symptom, without a cough or fever, something other than COVID-19 is the likely problem.
Can COVID-19 affect brain function?
COVID-19 does appear to affect brain function in some people. Specific neurological symptoms seen in people with COVID-19 include loss of smell, inability to taste, muscle weakness, tingling or numbness in the hands and feet, dizziness, confusion, delirium, seizures, and stroke.
One study that looked at 214 people with moderate to severe COVID-19 in Wuhan, China found that about one-third of those patients had one or more neurological symptoms. Neurological symptoms were more common in people with more severe disease.
Neurological symptoms have also been seen in COVID-19 patients in the US and around the world. Some people with neurological symptoms tested positive for COVID-19 but did not have any respiratory symptoms like coughing or difficulty breathing; others experienced both neurological and respiratory symptoms.
Experts do not know how the coronavirus causes neurological symptoms. They may be a direct result of infection or an indirect consequence of inflammation or altered oxygen and carbon dioxide levels caused by the virus.
The CDC has added "new confusion or inability to rouse" to its list of emergency warning signs that should prompt you to get immediate medical attention.
Is a lost sense of smell a symptom of COVID-19? What should I do if I lose my sense of smell?
Increasing evidence suggests that a lost sense of smell, known medically as anosmia, may be a symptom of COVID-19. This is not surprising, because viral infections are a leading cause of loss of sense of smell, and COVID-19 is a caused by a virus. Still, loss of smell might help doctors identify people who do not have other symptoms, but who might be infected with the COVID-19 virus — and who might be unwittingly infecting others.
A statement written by a group of ear, nose and throat specialists (otolaryngologists) in the United Kingdom reported that in Germany, two out of three confirmed COVID-19 cases had a loss of sense of smell; in South Korea, 30% of people with mild symptoms who tested positive for COVID-19 reported anosmia as their main symptom.
On March 22nd, the American Academy of Otolaryngology–Head and Neck Surgery recommended that anosmia be added to the list of COVID-19 symptoms used to screen people for possible testing or self-isolation.
In addition to COVID-19, loss of smell can also result from allergies as well as other viruses, including rhinoviruses that cause the common cold. So anosmia alone does not mean you have COVID-19. Studies are being done to get more definitive answers about how common anosmia is in people with COVID-19, at what point after infection loss of smell occurs, and how to distinguish loss of smell caused by COVID-19 from loss of smell caused by allergies, other viruses, or other causes altogether.
Until we know more, tell your doctor right away if you find yourself newly unable to smell. He or she may prompt you to get tested and to self-isolate.
How long is it between when a person is exposed to the virus and when they start showing symptoms?
Recently published research found that on average, the time from exposure to symptom onset (known as the incubation period) is about five to six days. However, studies have shown that symptoms could appear as soon as three days after exposure to as long as 13 days later. These findings continue to support the CDC recommendation of self-quarantine and monitoring of symptoms for 14 days post exposure.
How does coronavirus spread?
The coronavirus is thought to spread mainly from person to person. This can happen between people who are in close contact with one another. Droplets that are produced when an infected person coughs or sneezes may land in the mouths or noses of people who are nearby, or possibly be inhaled into their lungs.
A person infected with coronavirus — even one with no symptoms — may emit aerosols when they talk or breathe. Aerosols are infectious viral particles that can float or drift around in the air for up to three hours. Another person can breathe in these aerosols and become infected with the coronavirus. This is why everyone should cover their nose and mouth when they go out in public.
Coronavirus can also spread from contact with infected surfaces or objects. For example, a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes.