COVID-19 symptoms | Coronavirus | UC Davis Health

Influenza (flu) and COVID-19 are both contagious respiratory illnesses and they have similar symptoms. It may be difficult to tell the difference based on symptoms alone, but there are three key differences, according to the CDC:

• Those infected with COVID-19 sometimes experience change in or loss of taste and smell, which is less common with the flu.
• Flu usually begins with a cough, whereas COVID-19 most often starts with a fever.
• People infected with flu typically develop symptoms 1-4 days after infection. Those with COVID-19 typically develop symptoms 2-5 days after being infected. However, people infected with COVID-19 can show symptoms as late as 14 days after infection.

Symptoms of the common cold are usually mild. You could have a runny nose, cough, and sore throat. However, you won't have as much of a fever and likely won't feel as achy – both of which typically come with COVID-19 and the flu.

Learn more about the flu and how to get your flu shot from UC Davis Health

Most people who test positive for COVID-19 typically experience symptoms for a couple weeks. People who have long-haul COVID-19 symptoms, also called "long COVID," can experience health problems for four or more weeks after first being infected, according to the CDC.

The CDC says you should watch for these more severe symptoms, in which you should seek emergency medical attention:

• trouble breathing
• persistent pain or pressure in the chest
• new confusion
• inability to wake up or stay awake
• pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone

**This is not a list of all possible severe symptoms. Call your health care provider for any symptoms that are concerning to you.

Typically, vaccinated people who test positive for COVID-19 are either asymptomatic or have very mild symptoms. It is less common that infection will result in hospitalization or death. Their symptoms are more like those of a common cold, such as cough, fever or headache, with the addition of significant loss of smell.

No vaccine is 100% effective. Health experts continue to see that the risk of infection, hospitalization, and death are much lower in vaccinated people compared to unvaccinated.

Learn more about the COVID-19 vaccine and how to schedule your shot

If someone is showing these symptoms, you should seek emergency medical care immediately:

• trouble breathing
• persistent pain or pressure in the chest
• new confusion
• inability to wake or stay awake
• bluish lips or face

This is not a complete list of possibly symptoms. Call your primary care provider for any other symptoms that seem severe or are a concern to you.

Fever and cough are the most common COVID-19 symptoms in children, according to the CDC. "The symptoms of COVID-19 are similar in adults and children and can look like other common illnesses, like colds, strep throat, or allergies," the CDC reports.

In addition to the COVID-19 symptoms listed above, children may also experience:

• stomachache
• poor appetite
• poor feeding, especially for babies under 1 year old.

In some children, fever may be the only sign of COVID-19 infection.

COVID-19 symptoms can last weeks or months for some people, known as "long haulers". These people have, in theory, recovered from the worst impacts of COVID-19 and are no longer contagious. However, they still have symptoms. There seems to be no consistent reason for the symptoms to stay around so long.

This condition can affect anyone – old and young, otherwise healthy people and those battling other conditions. It has been seen in those who were hospitalized with COVID-19 and patients with very mild symptoms. However, it appears to be less common in children compared to adults. Additionally, it's less common for those who have breakthrough infections (vaccinated people) to get the virus vs. unvaccinated people.

Learn more about COVID-19 long haulers

COVID-19 infection can cause inflammation and damage to the heart muscle and inflammation to the covering of the heart. According to the CDC, this heart damage can explain why some people have reported long-term symptoms like:

• shortness of breath
• chest pain
• heart palpitations

Those infected with COVID-19 can also experience lasting lung problems. Prolonged illness and continued symptoms can occur even in young adults without chronic medical conditions. This could lead to an extended absence from work, studies, or other activities. Researchers are still investigating what other short- and long-term health effects are associated with COVID-19.

Learn more about the long-term symptoms of COVID-19