COVID-19 most commonly causes fever, cough, sore throat, runny or stuffy nose, fatigue, headache, and body aches. Symptoms typically appear 2 to 14 days after exposure. Most people recover within a week or two, but the illness can range from barely noticeable to severe, depending on factors like age, vaccination status, and underlying health conditions.
The Most Common Symptoms
COVID-19 shares many symptoms with other respiratory infections, which is part of what makes it tricky to identify without a test. The symptoms most people experience include:
- Sore throat
- Runny or stuffy nose
- Cough (often dry)
- Fatigue
- Headache
- Fever
- Muscle aches
For many people, especially those who are vaccinated, COVID feels like a bad cold or mild flu. Congestion, a scratchy throat, and tiredness are frequently the first signs. Fever may or may not be present, and when it does occur, it can be low-grade.
Digestive and Less Obvious Symptoms
COVID doesn’t always stay in your nose and throat. Roughly 60% of hospitalized COVID patients in one large multinational study reported gastrointestinal symptoms, including nausea, diarrhea, loose stools, and a sense of urgency. Earlier research estimated diarrhea in about 7% and nausea or vomiting in about 5% of cases overall. These numbers suggest digestive symptoms are more common than many people realize, especially in more serious infections.
Some people also experience shortness of breath, which never occurs with a regular cold. Loss of taste or smell was one of the hallmark signs early in the pandemic. It’s become less common with newer variants but hasn’t disappeared. Among people infected with the Omicron variant, about 20% reported mild to moderate changes in their sense of smell, and roughly 5% experienced severe or total loss.
How COVID Differs From a Cold or Flu
The overlap between COVID, colds, and the flu is significant, but a few patterns can help you tell them apart. According to a comparison from the Mayo Clinic, headache and fatigue are common with COVID but rare with a cold. Muscle aches happen with COVID and the flu but not typically with colds. Shortness of breath can occur with COVID and is essentially never a cold symptom. And loss of taste or smell, particularly without much nasal congestion, still points more toward COVID than anything else.
Timing matters too. Cold symptoms usually show up 1 to 3 days after exposure. COVID symptoms take longer, typically appearing 2 to 14 days after you’ve been exposed. If you develop a sore throat and congestion a full week after being around someone who was sick, COVID is more likely than a cold.
The only reliable way to distinguish COVID from a cold or flu is a test. Home rapid antigen tests are widely available and give results in about 15 minutes.
Symptoms in Children
Children get COVID too, though they tend to have milder cases than adults. The most common symptoms in kids are fever and cough, followed by sore throat, runny nose, headache, fatigue, and digestive issues like nausea, vomiting, or diarrhea. During periods of high Omicron transmission, doctors reported a notable increase in croup, the barking cough caused by swelling in the upper airway, in young children with COVID.
One challenge with kids is that COVID symptoms look nearly identical to every other childhood illness. A child with a fever and runny nose could have COVID, the flu, RSV, or a common cold. Testing is the only way to know for sure.
Vaccinated vs. Unvaccinated Symptoms
Vaccination doesn’t eliminate the chance of getting COVID, but it significantly changes what the illness looks like. Among breakthrough infections documented by the CDC, 27% were completely asymptomatic, meaning the person tested positive but never felt sick at all. Only about 10% required hospitalization, and among those hospitalized, nearly a third were actually admitted for unrelated reasons and happened to test positive.
When vaccinated people do develop symptoms, they tend to be milder and resolve faster. The illness more often resembles a cold: congestion, a sore throat, maybe a day or two of fatigue. Severe outcomes like pneumonia and respiratory failure are far more concentrated among unvaccinated individuals and those with weakened immune systems.
Emergency Warning Signs
Most COVID cases resolve at home. But certain symptoms signal that the illness is becoming dangerous and needs immediate medical attention:
- Trouble breathing or feeling like you can’t get enough air
- Persistent chest pain or pressure
- New confusion or difficulty thinking clearly
- Inability to stay awake or difficulty being roused from sleep
- Color changes in lips, nail beds, or skin that appear pale, gray, or blue (this can be harder to spot on darker skin tones, so check nail beds and lips closely)
These signs suggest your body isn’t getting enough oxygen or that the virus is affecting your brain. They warrant a call to 911.
When Symptoms Don’t Go Away
For some people, COVID symptoms linger or new ones appear well after the initial infection clears. This is long COVID, defined as symptoms that persist for at least three months after infection. The symptoms are wide-ranging and can include fatigue, brain fog, shortness of breath, heart palpitations, joint pain, and sleep problems, among others.
Long COVID symptoms don’t always follow a straight line. They can improve, worsen, disappear for weeks, and then return. This unpredictable pattern is one of the things that makes the condition so frustrating. It can follow even a mild initial infection, and it affects people of all ages. If your symptoms haven’t resolved after a few months, or if new symptoms have appeared since your infection, that pattern is worth discussing with a healthcare provider.