Symptoms-Risks COVID-19 Symptoms and Risks Q&A

​​​Note: This Guidance is no longer in effect and is for historical purposes only. ​​

COVID-19 Symptoms and Risks Q&A

What are the common symptoms of COVID-19?

  • Fever or chills

  • Cough

  • Shortness of breath or difficulty breathing

  • Fatigue (tiredness)

  • Muscle or body aches

  • Headache

  • New loss of taste or smell

  • Sore throat

  • Congestion or runny nose

  • Nausea or vomiting

  • Diarrhea

What are the similarities and differences between Influenza (flu) and COVID-19?

Influenza (flu) and COVID-19 are both contagious respiratory illnesses, but they're caused by different viruses. COVID-19 is caused by a new coronavirus (called SARS-CoV-2) and the flu is caused by influenza viruses

Flu symptoms and COVID-19 are similar. It is hard to tell the difference between them without testing. Cases of COVID-19 and flu can cause different levels of illness, including no symptoms (asymptomatic) to severe symptoms. See below for common and major differences in symptoms.

The CDC has more information about similarities and differences between the flu and COVID-19.

What is the major symptom difference between COVID-19 and the flu?

A new loss of taste or smell may occur with a COVID-19 infection, but it will not with the flu.

Who is at risk of infection with coronavirus, which causes COVID-19?

Anyone can get infected with the new coronavirus, but fully vaccinated people are unlikely to become infected. Currently, those at greatest risk of infection are persons who are not fully vaccinated who have had prolonged, unprotected close contact (within six feet for at least 15 minutes or more during a 24-hour period) with a person with confirmed COVID-19 infection, regardless of whether the infected person has symptoms. People who are not fully vaccinated who are in group settings (like homeless shelters, assisted living facilities, or college dormitories) are at increased risk of acquiring infection because of the increased likelihood of close contact.

Everyone can reduce the risk to themselves and others by:

What is the risk of children getting sick with COVID-19?

Children can be infected with the new coronavirus and can get sick with COVID-19 but fewer children have been sick with COVID-19 compared to adults.

Most children with COVID-19 have mild symptoms, or they may be asymptomatic, meaning they have no symptoms at all. However, children with certain underlying medical conditions and infants (less than one year old) might be at increased risk for severe illness from COVID-19. Some children have developed a rare but serious disease that is linked to COVID-19 called multisystem inflammatory syndrome (MIS-C).

For more information for parents or caregivers of children, see the CDC's page on Children and Teens  and their COVID-19 Parental Resources Kit.

For more information about how people get sick with the virus that causes COVID-19, see How COVID-19 Spreads.

What should I do if my child has COVID-19 symptoms?

If your child gets sick with symptoms of COVID-19, take these steps: 

  • Keep your child at home

  • Call your child's doctor to discuss whether they need to be tested for COVID-19 

If you are unsure if your child's symptoms are related to COVID-19, visit the Coronavirus self-checker. This online tool will help you decide when to seek testing or medical care for your child. 

If you don't have health insurance or a regular doctor, call Medi-Nurse. Medi-Nurse is a free, 24/7 nurse advice line available at 1‑877‑409‑9052. You can speak directly with a healthcare professional about your child's symptoms, get advice on testing and treatment in your area, or ask how to apply for health insurance.

It's also important to protect yourself from COVID-19 while caring for your sick child.

If your child attends school or childcare, notify them that your child is sick and about your child's COVID-19 test results. Review policies for your child's school or childcare facility related to when a child can return after being sick.

Your child may return to school, childcare, or other in-person activities only after they can safely be around others. Discuss this with your child's doctor. If your child is sick but doesn't have COVID-19, they may still need to stay home for some time.

In a medical emergency, call 911 or bring your child to the emergency room. Do not delay seeking emergency care for your child because you are worried about the spread of COVID-19. Emergency rooms have infection prevention plans to protect you and your child from getting sick with COVID-19.

If your child is showing any of these emergency warning signs, seek emergency medical care immediately:

  • Trouble breathing

  • Pain or pressure in the chest that doesn't go away

  • New confusion

  • Can't wake up or stay awake when not tired

  • Bluish lips or face

Call your child's healthcare provider for any other symptoms that are severe or concerning to you.

See the Guidance on Returning to Work or School Following COVID-19 Diagnosis and CDC's COVID-19 in Children and Teens for more details.

What are the long-term effects of COVID-19?

COVID-19 has not existed long enough for us to really know. We are learning that many organs besides the lungs are affected by COVID-19, and there are many ways it can affect someone's health.

While most people with COVID-19 recover and return to normal health, some patients have symptoms that can last for weeks or even months after recovery from acute illness. Even people who are not hospitalized and have mild or no symptoms can experience persistent or late symptoms. People with long COVID report experiencing different combinations of the following symptoms:

  • Tiredness or fatigue

  • Difficulty thinking or concentrating (sometimes referred to as "brain fog")

  • Headache

  • Loss of smell or taste

  • Dizziness on standing

  • Fast-beating or pounding heart (also known as heart palpitations)

  • Chest pain

  • Difficulty breathing or shortness of breath

  • Cough

  • Joint or muscle pain

  • Depression or anxiety

  • Fever

  • Symptoms that get worse after physical or mental activities

COVID-19 can affect most, if not all, body systems including heart, lung, kidney, skin, and brain functions. Multiorgan effects can also include conditions that occur after COVID-19, like multisystem inflammatory syndrome (MIS) and autoimmune conditions. MIS is a condition where different body parts can become swollen. Autoimmune conditions happen when your immune system attacks healthy cells in your body by mistake, causing painful swelling in the affected parts of the body.

The long-term significance of these effects is not yet known. See the CDC's Long-Term Effects of COVID-19 for more details.

Post-COVID conditions also can include the longer-term effects of COVID-19 treatment or hospitalization. Some of these longer-term effects are similar to those related to hospitalization for other respiratory infections or other conditions.

Effects of COVID-19 treatment and hospitalization can also include post-intensive care syndrome (PICS), which refers to health effects that remain after a critical illness. These effects can include severe weakness and post-traumatic stress disorder (PTSD). PTSD involves long-term reactions to a very stressful event.

Can people who recover from COVID-19 be reinfected?

Reinfection can occur, but it is rare, and patients are unlikely to be reinfected in the months after they recover. However, the duration of immunity to COVID-19 infection is not yet understood.

Who needs to quarantine?

If you are not fully vaccinated or have not had COVID-19 infection in the past three months, you should self-quarantine if you have had close contact with someone who has COVID-19.

Close contact means:

  • You were within six feet of someone who has COVID-19 for 15 minutes or more during a 24-hour period

See the CDPH Travel page for travel related recommendations.

Can COVID-19 be spread by airborne transmission?

Yes, under certain conditions, people with COVID-19 have infected others who were more than six feet away. From published reports, factors that increase the risk of airborne transmission of the virus that causes COVID-19 include:

  • Being in enclosed spaces with inadequate ventilation or air handling within which the concentration of exhaled respiratory aerosols can build-up in the air space.

  • Increased exhalation of respiratory aerosols by the infectious person if they are engaged in physical exertion or raise their voice (e.g., exercising, shouting, singing).

  • Prolonged exposure to these conditions, typically more than 15 minutes. The people who were infected were in the same space during the same time or shortly after the person with COVID-19 had left.

How do I protect myself and others from COVID-19?

The best way to prevent COVID-19 infection is to get vaccinated. You can also avoid being exposed to the virus that causes COVID-19 by taking these steps:

Learn more about what you can do to protect yourself and others.

Can air conditioning spread COVID-19 from one room to another?

There is no evidence that COVID-19 spreads indoors through air conditioning. There are a wide variety of heating, ventilation, and air conditioning (HVAC) systems. Well-designed HVAC systems can help reduce risk of transmission. Well-designed systems filter air as it circulates, it adds cleaner air to the space. Introduction of fresh outdoor air dilutes the concentration of infectious particles. Air conditioning is also necessary in some areas to protect from excessive heat.

For more information, see:

What do I need to know about COVID-19 and wildfire smoke?

Air pollutants from wildfire smoke can irritate the lungs, cause inflammation, weaken your immune system, and increase your risk of respiratory infections like COVID-19. Also, wildfire smoke exposure can worsen COVID-19 symptoms and outcomes.

Keep in mind that some respiratory symptoms from wildfire smoke exposure and COVID-19 may be similar. These include:

  • Cough

  • Sore throat

  • Difficulty breathing

COVID-19 symptoms that are unrelated to smoke exposure include fever or chills, muscle or body aches, and diarrhea. If you think you may have COVID-19, contact your doctor.

The CDC has more detailed information about wildfire smoke and COVID-19.

Are there additional resources that I can use to keep myself and my family safe?

Originally Published on 6/11/2021