COVID-19 can cause a wide range of symptoms, from mild cold-like discomfort to severe breathing problems. Symptoms typically appear 2 to 14 days after exposure to the virus, though with more recent variants most people notice them within 2 to 5 days. The full list of possible symptoms is long, and not everyone experiences the same combination.
The Most Common Symptoms
The CDC lists these as possible symptoms of COVID-19:
- Fever or chills
- Cough
- 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
Earlier in the pandemic, the most frequently reported symptoms were cough (84% of patients), fever (80%), muscle aches and chills (63%), fatigue (62%), headache (59%), and shortness of breath (57%). Those numbers have shifted over time as the virus has evolved.
How Symptoms Have Changed With Newer Variants
The original strains of COVID-19 were known for causing significant lower respiratory problems, including pneumonia and severe shortness of breath. Loss of taste and smell was also a hallmark early on. Omicron and its subvariants shifted the pattern. These strains tend to cause symptoms that feel more like a bad cold: runny nose, sore throat, congestion, and fatigue. Lower respiratory symptoms like deep coughing and trouble breathing are less common with Omicron infections, though they still occur, especially in people at higher risk.
Loss of taste and smell still happens but is reported far less frequently than it was in 2020 and 2021. If you’re infected today, a scratchy or painful sore throat and heavy congestion are more likely to be your first noticeable symptoms.
Digestive Symptoms Are More Common Than Many Expect
COVID-19 isn’t just a respiratory illness. Nausea, vomiting, and diarrhea affect a meaningful number of people. Studies have found diarrhea in roughly 10% to 34% of patients, depending on the population studied, and nausea or vomiting in about 10% to 26%. For some people, these digestive symptoms appear before any cough or fever, which can make early identification tricky.
People who develop digestive symptoms also tend to have a longer overall illness. The virus can be detected in stool samples for an average of about 28 days after symptoms start, compared to roughly 17 days in respiratory samples. This doesn’t necessarily mean you’re contagious for that entire period, but it does reflect how deeply the virus can affect the gut.
How COVID-19 Differs From the Flu and Common Cold
The honest answer is that you can’t reliably tell COVID-19 apart from the flu or a cold based on symptoms alone. The CDC is explicit about this: testing is the only way to confirm which virus you have. Fever, cough, body aches, sore throat, congestion, and fatigue are shared across all three.
There are a few subtle patterns worth knowing. COVID-19 has a longer incubation period (2 to 5 days on average, sometimes up to 14) compared to the flu (1 to 4 days). So if you were exposed to something and symptoms showed up the very next day, the flu is statistically more likely. Loss of taste or smell, while less common now, still occurs more frequently with COVID-19 than with influenza. COVID-19 also tends to make you contagious for longer. On average, people with COVID-19 are considered contagious for about 8 days after symptoms begin, and they can start spreading the virus 2 to 3 days before they feel sick. With the flu, contagiousness peaks in the first 3 days of illness.
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, and digestive symptoms like nausea, vomiting, and diarrhea also occur. Most children experience mild illness or no symptoms at all.
One pattern that emerged during the Omicron wave was a noticeable increase in croup, the barking cough caused by swelling around the voice box and windpipe. This was reported in young children even as other respiratory viruses known to cause croup were declining, suggesting Omicron itself was the trigger. Because COVID-19 symptoms in children overlap so heavily with other common childhood infections, testing is especially important for identification.
A rare but serious complication in children is multisystem inflammatory syndrome (MIS-C), which can develop weeks after a COVID-19 infection. It involves persistent high fever, inflammation across multiple organs, and often requires intensive care. More than half of children diagnosed with MIS-C need ICU-level treatment. MIS-C has become less common with widespread immunity from vaccination and prior infection, but it remains something to watch for in the weeks following a child’s COVID-19 illness.
Emergency Warning Signs
Most COVID-19 infections resolve at home, but certain symptoms signal that something more dangerous is happening. Seek emergency care if you or someone else develops:
- Trouble breathing
- Persistent pain or pressure in the chest
- New confusion or difficulty thinking clearly
- Inability to wake up or stay awake
- Pale, gray, or blue-colored skin, lips, or nail beds
The skin color changes can be harder to spot on darker skin tones, so pay close attention to the lips, nail beds, and gums. These warning signs can indicate dangerously low oxygen levels or organ stress that requires immediate treatment.
When Symptoms Don’t Go Away: Long COVID
For most people, acute COVID-19 symptoms resolve within a couple of weeks. But a significant number of people develop symptoms that persist for months or even years after the initial infection. This is known as Long COVID, and researchers have identified more than 200 symptoms associated with it.
The three most commonly reported Long COVID symptoms are fatigue, brain fog (difficulty concentrating, memory problems, mental sluggishness), and post-exertional malaise, which means symptoms flare up or worsen after physical or mental effort. Other frequent complaints include ongoing shortness of breath, headaches, sleep problems, joint pain, and mood changes.
Most people with Long COVID see significant improvement within 3 months. Others take much longer, with some not experiencing meaningful recovery for a year or more. Long COVID can follow even a mild initial infection, and it remains one of the least predictable aspects of the disease.