COVID-19 most commonly causes sore throat, congestion, cough, fatigue, and body aches. Symptoms typically appear 3 to 6 days after exposure and last up to 10 days, though some people feel sick for longer. The specific mix of symptoms you experience can vary based on the circulating variant, whether you’ve been vaccinated, and your overall health.
The Most Common Symptoms
COVID shares many symptoms with other respiratory infections, which is part of what makes it tricky to identify without a test. The CDC lists these as possible symptoms:
- Fever or chills
- Cough (often dry)
- Shortness of breath or difficulty breathing
- Sore throat
- Congestion or runny nose
- New loss of taste or smell
- Fatigue
- Muscle or body aches
- Headache
- Nausea or vomiting
- Diarrhea
Not everyone gets all of these, and many people experience only a handful. For most adults, the illness feels like a bad cold or mild flu, with sore throat and congestion dominating the early days, followed by fatigue that can linger after the other symptoms improve.
Gut Symptoms Are More Common Than You’d Think
COVID isn’t just a respiratory illness. Nearly 40% of patients report gastrointestinal symptoms, mainly loss of appetite, nausea, vomiting, and diarrhea. Some people develop digestive problems before the more recognizable respiratory symptoms show up, which can make early COVID easy to mistake for a stomach bug. About 10% to 18% of positive cases involve diarrhea specifically, with higher rates among hospitalized patients.
How COVID Differs From a Cold or Flu
The overlap between COVID, the flu, and a common cold is significant, but a few patterns can help narrow things down. Fatigue and headache are common with both COVID and the flu, but rare with a cold. Fever is more reliably present with the flu than with COVID, where it only appears sometimes. Muscle aches show up with COVID and the flu but essentially never with a cold.
The most distinctive COVID symptom is a sudden loss of taste or smell, especially when it happens early in the illness and without much nasal congestion. Colds and allergies can dull your sense of smell by blocking your nose, but COVID can knock it out even when your nasal passages are relatively clear. That said, loss of smell has become less common with newer variants than it was in 2020 and 2021. The only reliable way to tell these illnesses apart is testing.
Why COVID Can Erase Your Sense of Smell
The virus doesn’t directly infect the nerve cells responsible for smell. Instead, it attacks the supporting cells that surround them in the lining of the nasal cavity, triggering inflammation and damage that disrupts the nerve cells’ ability to function. The good news is that this tissue can regenerate. In one study, 61% of patients had fully normal smell function within 8 weeks. Another 22% had only mild lingering dysfunction. About 4% still had severe loss at that point, and for a small number of people, full recovery takes much longer or doesn’t happen completely, because the regenerated tissue can end up thinner and patchier than the original.
How Vaccination Changes the Picture
If you’ve been vaccinated, your symptoms are likely to look a bit different from someone who hasn’t. Vaccinated people actually report more upper respiratory symptoms during the acute phase: sore throat is 72% more common, nasal congestion 50% more common, and cough 44% more common compared to unvaccinated cases. This might seem counterintuitive, but these upper respiratory symptoms tend to be no more severe, and the trade-off is significant.
Vaccinated people are 46% less likely to experience difficulty breathing during the acute illness, and that gap widens over time: 75% less likely by 90 days after infection. Other symptoms like fatigue, muscle aches, chills, sleep problems, loss of smell or taste, headaches, and cognitive issues are also less common in vaccinated people in the weeks following infection. Overall symptom severity scores are consistently lower at every stage of the illness for vaccinated individuals.
Long COVID rates reflect this difference too. About 27% of unvaccinated people developed long COVID by 90 days after infection, compared to 8% of vaccinated people, a roughly threefold reduction in risk.
Symptoms in Children
Children get many of the same symptoms as adults, with fever and cough being the most common. Sore throat, runny nose, headache, fatigue, shortness of breath, and gastrointestinal symptoms like nausea, vomiting, or diarrhea also occur. The key difference is severity: most children with COVID experience either no symptoms at all or only mild illness. Asymptomatic infection is particularly common in younger kids, which means a child can test positive without ever seeming sick.
When Symptoms Don’t Go Away
For most people, acute COVID resolves within about 10 days. But some develop symptoms that persist for weeks, months, or even years afterward. This is commonly called long COVID, and more than 200 distinct symptoms have been linked to it. The three most frequently reported are fatigue that interferes with daily life, brain fog (difficulty thinking or concentrating), and a worsening of symptoms after physical or mental exertion.
Other common long COVID symptoms include shortness of breath, heart palpitations, chest pain, headaches, sleep problems, dizziness when standing, pins-and-needles sensations, changes in taste or smell, depression or anxiety, diarrhea, stomach pain, joint or muscle pain, rash, and changes in menstrual cycles. These symptoms can come and go unpredictably, resolving for a stretch and then returning.
Most people with long COVID see significant improvement within 3 months, but others may not improve for much longer. There’s no lab test that can confirm long COVID. Diagnosis is based on a pattern of symptoms that developed after a COVID infection and can’t be explained by another condition.