How long are you contagious after testing positive for COVID-19?
Tested positive for COVID-19? Learn how long you may be contagious and what precautions to take to help stop the spread.
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Key takeaways
- Airborne transmission makes COVID-19 contagious.
- You can be contagious for 1-2 days before symptoms appear and up to 8-10 days following symptom onset.
- You can spread the virus even if you do not have symptoms.
- Social distancing should continue until, for at least 24 hours, symptoms improve and you’re fever-free without medications.
- Vaccination can help reduce severity and transmission risk.
- If you get COVID-19, treatment options are available to reduce the risk of developing severe COVID-19.
Just like other viruses, COVID-19 can spread from person to person. Knowing more about how the virus spreads, when people are contagious, and what precautions are most effective—such as wearing a well-fitting mask, physical distancing, practicing good hygiene, and staying up to date on vaccinations—can help limit transmission and protect those at higher risk.
What is a virus?
To understand how COVID-19 behaves, it helps to first understand what a virus is and how it affects the body. A virus is a tiny invader made of genetic material (either DNA or RNA) wrapped in a protective protein shell. Unlike bacteria, viruses can’t live or grow on their own. To survive and multiply, they must enter normal living cells.
Once inside, the virus takes over the cell’s machinery to make more copies of itself. Viruses can spread through the air, by direct contact, or via contaminated surfaces, and can cause many kinds of illnesses, from the common cold to the flu.
How does COVID-19 spread?
COVID-19 is caused by the SARS-CoV-2 virus, which spreads primarily through the air when an infected person breathes, talks, coughs, or sneezes.
Airborne illnesses like COVID-19 are especially contagious because they spread through tiny droplets or particles that can linger in the air and travel beyond close contact. When an infected person breathes, talks, coughs, or sneezes, they release droplets and aerosols.
Small droplets and particles can remain in the air for minutes to hours, especially in poorly ventilated indoor spaces, even after an infected person has left the room. That’s why additional prevention strategies like staying away from others, wearing a well-fitting mask, and ventilation can help curb disease spread.
People can spread COVID-19 even before they feel sick, and some infected individuals never develop symptoms. This type of transmission makes controlling airborne viruses more challenging than those that rely on direct contact or associated with more easily recognized signs of illness.
How long are you contagious with COVID-19?
Because COVID-19 can spread before symptoms appear—or even when no symptoms develop—it’s important to know how long you might be contagious and what precautions you can take during that time. If you tested positive for COVID-19, you can be contagious for 1-2 days before symptoms appear and up to 8-10 days following. Most people spread COVID-19 in the first few days before and after symptoms appear.
According to the Centers for Disease Control and Prevention (CDC), you should stay home and away from others until, for at least 24 hours, your symptoms are improving, and you’ve been fever-free without medication.
After returning to normal routines, the CDC recommends that people take extra steps for the next five days to help prevent illness from spreading. Practicing good hygiene, wearing a well-fitting mask, and keeping distance from others where possible can be helpful to curb the spread of COVID-19.
It is important to know that feeling better doesn’t always mean you’re no longer contagious; how long you were sick and how sick you were can affect how likely you are to spread the virus. And some people can spread COVID-19 before they experience symptoms.
People with weakened immune systems can also be contagious for longer.
1-10
days
Why do people respond to COVID-19 differently?
Not everyone who gets COVID-19 experiences it the same way. The body’s response to the virus can vary widely depending on several factors. Some people experience no symptoms, while others develop severe or even life-threatening illness, leading to inflammation, organ damage or respiratory failure. This variation can be due to a combination of factors:
- Immune system: People with weakened immune systems have a harder time fighting COVID-19.
- Age: Older adults are more likely to experience severe symptoms.
- Race and ethnicity: People from certain racial and ethnic minority groups are likely to face barriers accessing health care and, if they get COVID-19, are more likely to be hospitalized, be admitted to the intensive care unit, and die from it at younger ages.
- Underlying health conditions: Chronic illnesses like diabetes, heart disease, or lung conditions like asthma. Take a Risk Assessment to determine if you’re at high risk for severe COVID-19.
- Vaccination status: Unvaccinated individuals are more likely to experience severe illness or hospitalization.
When do COVID-19 symptoms start?
COVID-19 symptoms typically appear 2–14 days after exposure. This is called the incubation period, which is the time between exposure to an infection and the appearance of the first symptoms. You can be contagious 1–2 days before symptoms begin, which is why the virus can spread so easily.
Some COVID-19 symptoms include:
- Fever or chills
- Cough
- Fatigue
- New loss of taste or smell
- Sore throat
- Headache
- Shortness of breath
Some people, however, never develop symptoms but can still spread the virus. If you test positive but feel fine, you should still take precautions, such as wearing a well-fitting masks, keeping physical distance from others, and practicing good hygiene for at least 5 days.
The role of vaccination
Vaccination can help reduce the risk of severe illness and limit the spread of the virus. While no vaccine offers 100% protection, vaccinated people are:
- Less likely to develop severe symptoms
- Less likely to transmit the virus to others
For people at high risk—such as older adults or those with chronic conditions—vaccination can help reduce the overall burden on healthcare systems and help to protect vulnerable communities.
For people who do get sick with COVID-19, treatments are available that can help prevent severe illness and death when started within 5-7 days of symptoms. If you think you may have COVID-19, talk to a healthcare provider.
COVID-19 is caused by the SARS-CoV-2 virus, which spreads primarily through the air when an infected person breathes, talks, coughs, or sneezes.
COVID-19 is contagious but there are things you can do to help reduce your risk
COVID-19 tends to be most contagious in the first 1-2 days before and up to 8-10 days after symptoms begin. It’s important to monitor your symptoms and follow the guidance of your healthcare provider. Taking precautions—like staying away from others, wearing a well-fitting mask, and staying up to date on vaccinations—can help curb the spread of COVID-19. Talk to a healthcare provider if you think you may have COVID-19.
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References
ACEP COVID-19 Field Guide. American College of Emergency Physicians. Accessed August 1, 2025. https://www.acep.org/corona/covid-19-field-guide/home-safety/self-isolation
CDC updates and simplifies respiratory virus recommendations. The Centers for Disease Control and Prevention Newsroom. March 1, 2024. Accessed August 7, 2025. https://
www.cdc.gov/media/releases/2024/p0301-respiratory-virus.html
Preventing Spread of Respiratory Viruses When You're Sick. The Centers for Disease Control and Prevention. August 18, 2025. Accessed August 28, 2025. https://
www.cdc.gov/respiratory-viruses/prevention/precautions-when-sick.html
Gregory, CO and Hall AJ. CDC Yellow Book: Health Information for International Travel. The Centers for Disease Control and Prevention. April 23, 2025. Accessed August 1, 2025. https://www.cdc.gov/yellow-book/hcp/travel-associated-infections-diseases
/covid-19.html
How to Protect Yourself and Others From COVID-19. MedlinePlus. January 1, 2025. Accessed August 29, 2025. https://medlineplus.gov/ency/
patientinstructions/000973.htm
People with Certain Medical Conditions and COVID-19 Risk Factors. The Centers for Disease Control and Prevention. June 11, 2025. Accessed August 1, 2025. https://
www.cdc.gov/covid/risk-factors/index.html
Symptoms of COVID-19. The Centers for Disease Control and Prevention. March 10, 2025. Accessed August 1, 2025. https://www.cdc.gov/covid/signs-symptoms/index.html
Taylor MW. What Is a Virus?. Viruses and Man: A History of Interactions. 2014;23-40. Published 2014 Jul 22. doi:10.1007/978-3-319-07758-1_2
Types of COVID-19 Treatment. The Centers for Disease Control and Prevention. May 8, 2025. Accessed August 1, 2025. https://www.cdc.gov/covid/treatment/index.html
Underlying Conditions and the Higher Risk for Severe COVID-19. The Centers for Disease Control and Prevention. February 6, 2025. Accessed August 1, 2025. https://
www.cdc.gov/covid/hcp/clinical-care/underlying-conditions.html
van Doremalen N, Bushmaker T, Morris DH, et al. Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. N Engl J Med. 2020;382(16):1564-1567. doi:10.1056/NEJMc2004973
Viral Infection. MedlinePlus. November 8, 2023. Accessed August 29, 2025. https://
medlineplus.gov/viralinfections.html