COVID-19 symptoms typically start with fever, followed by cough, body aches, and fatigue. Symptoms usually appear 3 to 6 days after exposure and last up to 10 days in most people. Nearly all symptomatic patients (96%) experience at least one of the three hallmark signs: fever, cough, or shortness of breath.
The Most Common Symptoms
Among the symptoms reported most frequently, cough tops the list at about 84% of symptomatic patients, followed by fever at 80%. Muscle pain and chills each affect roughly 63% of people, fatigue hits about 62%, headache 59%, and shortness of breath 57%. You might experience all of these at once or just a few. Around 45% of patients report the classic trio of fever, cough, and shortness of breath together.
Other symptoms that show up regularly include sore throat, congestion or runny nose, and loss of taste or smell. That last one became strongly associated with COVID-19 early in the pandemic. With Omicron-related variants, about 44% of patients still report some change in taste or smell, though many cases are mild and resolve within weeks. About 23% lose both senses simultaneously, while around 19% notice taste changes without smell problems.
Digestive Symptoms
Roughly half of COVID-19 patients experience at least one gastrointestinal symptom during their infection. Diarrhea is the most common, reported by about 38% of patients, while nausea and vomiting are less frequent (around 13%). These gut symptoms sometimes appear before respiratory symptoms like cough, which is unusual compared to other respiratory infections. The virus can directly infect cells lining the digestive tract because those cells have high concentrations of the receptor the virus uses to enter cells. The resulting inflammation can also disrupt normal gut bacteria, which contributes to symptoms like bloating, cramping, and loose stools.
How Symptoms Typically Progress
Fever is usually the first symptom to appear. Within a day or two, cough and sore throat tend to follow, along with body aches and headache. Some people experience nausea or vomiting early on, sometimes even before the cough starts. This pattern varies significantly from person to person, so there’s no single reliable timeline.
Most infections resolve within about 10 days. In severe cases, which are far less common now than in earlier waves of the pandemic, breathing difficulties can worsen around day 7 to 10 after symptom onset. Current variants don’t appear to cause different symptoms than earlier ones. The shift toward generally milder illness is likely because most people now carry some immunity from prior infections, vaccinations, or both.
COVID-19 vs. the Flu vs. a Cold
You genuinely cannot tell COVID-19 apart from the flu based on symptoms alone. Both cause fever, cough, body aches, fatigue, sore throat, congestion, and headache. Testing is the only reliable way to know which virus you have.
There are a few subtle differences worth knowing. Loss of taste or smell is more strongly associated with COVID-19 than with the flu or a cold. COVID-19 also has a longer incubation period: 2 to 5 days (and up to 14), compared to 1 to 4 days for the flu. You’re also contagious longer with COVID-19, averaging about 8 days from symptom onset, compared to roughly the first 3 days for the flu. A common cold, by contrast, rarely causes fever or significant body aches and tends to stay in the nose and throat.
Symptoms in Children
Children get the same core symptoms as adults: fever, cough, sore throat, headache, muscle pain, fatigue, congestion, and sometimes nausea, vomiting, or diarrhea. Fever and cough are the most common. Most children have mild illness, and many are asymptomatic entirely. Infants under 1 year may only show a fever and reduced interest in feeding, with no other obvious signs.
Rare but serious complications in children include croup, inflammation of the heart muscle, and a condition called multisystem inflammatory syndrome in children (MIS-C). MIS-C typically appears 2 to 6 weeks after infection and involves persistent fever, abdominal pain, rash, red eyes, and sometimes dangerously low blood pressure. It requires immediate medical care but has become less common with rising population immunity.
When Symptoms Don’t Go Away: Long COVID
Long COVID is defined as symptoms or new health conditions that persist for at least 3 months after a COVID-19 infection. These symptoms can improve, worsen, or stay steady over time. There is no lab test that confirms long COVID. Routine blood work, chest X-rays, and heart tests often come back normal, which can be frustrating. Diagnosis is based on your health history and a confirmed or suspected prior infection.
Common long COVID symptoms include persistent fatigue, brain fog (difficulty concentrating or remembering things), shortness of breath, and heart palpitations. Digestive issues are also frequent. In one study, 16% of patients who had no prior gut problems developed new digestive symptoms about 100 days after infection, including abdominal pain, constipation, diarrhea, and vomiting. Others develop ongoing heartburn, trouble swallowing, bloating, or symptoms resembling irritable bowel syndrome. These problems appear to stem from the virus disrupting the communication between the gut and the brain, along with lingering inflammation that alters the balance of gut bacteria.