Covid Symptoms: Full List and Warning Signs

Covid symptoms most often include fever, chills, cough, shortness of breath, fatigue, muscle aches, headache, sore throat, a stuffy or runny nose, loss of taste or smell, and gastrointestinal upset. Symptoms may develop within 2 to 14 days after exposure, most often around day 5. The picture runs from no symptoms at all to critical illness, and the difference that matters clinically is breathing.

The list of covid symptoms

The MedlinePlus Medical Encyclopedia entry, last reviewed January 1, 2025, lists:

• Fever and chills
• Cough, and rarely coughing up blood
• Shortness of breath or difficulty breathing
• Fatigue
• Muscle aches
• Headache
• Loss of sense of taste or smell
• Sore throat
• Stuffy or runny nose
• Nausea and vomiting
• Diarrhea

Almost nobody gets all of them. Two or three is the common experience, and which two or three varies enough between people that the combination is not diagnostic on its own.

How soon symptoms start

“Symptoms may develop within 2 to 14 days after you are exposed to the virus. Most often, symptoms appear around 5 days after exposure.” StatPearls puts the median incubation period at 5.1 days, with most patients developing symptoms within 11.5 days.

The five severity levels clinicians use

The classification used in U.S. clinical practice has five rungs, and the dividing line between moderate and severe is a number:

Level	What defines it
Asymptomatic or presymptomatic	A positive test with no clinical symptoms
Mild	Symptoms present, without shortness of breath or abnormal chest imaging
Moderate	Evidence of lower respiratory disease, with oxygen saturation at or above 94% on room air
Severe	Oxygen saturation below 94% on room air, or a respiratory rate above 30 breaths per minute
Critical	Acute respiratory failure, septic shock, or multiple organ dysfunction

The overwhelming majority of cases sit in the first two rows and are managed at home. For what that course actually looks like day to day, see mild covid symptoms.

Emergency warning signs

MedlinePlus says to get emergency medical help for:

• Trouble breathing
• Chest pain or pressure that persists
• Confusion or inability to wake up
• Blue, gray or pale skin, lips, face or nail beds

These do not wait for a call-back or a next-day appointment.

What changed since 2020

Two things worth knowing before you use an old mental checklist.

First, loss of smell stopped being the giveaway it once was. A psychophysical case-control study measured olfactory dysfunction in 80.6% of D614G infections, 83.0% with alpha and 65.6% with delta, but only 36.3% with omicron. A later meta-analysis of 62 studies covering 626,035 omicron patients estimated global prevalence at about 3.7%, rising to 11.7% in people of European ancestry — a two- to tenfold drop against earlier variants. Smell loss still means something when it happens; its absence no longer means much of anything. The other causes are covered in loss of taste and smell causes.

Second, the core symptom set itself has been stable. Fever, cough, sore throat, congestion, headache and fatigue have described covid across every wave. What shifts between variants is how often each item appears, not the list — the reasoning is laid out in new covid variant symptoms.

Confirming it

Testing, by rapid antigen test or PCR, is the only way to separate covid from influenza, RSV or an ordinary cold, because the symptoms overlap almost entirely. That matters most for people eligible for antiviral treatment, where the window to start is measured in days from symptom onset.

One note on sourcing: this page is built from MedlinePlus, StatPearls and the peer-reviewed literature. The CDC’s own symptom pages block automated access, so nothing here is attributed to them — check cdc.gov directly for current federal guidance on testing and isolation, which changes more often than the symptom list does.

When symptoms outlast the infection

Some people are left with symptoms that continue or appear well after the acute illness. That has a formal U.S. definition and its own page: long covid symptoms. In children, the acute picture and the warning signs differ enough to be worth reading separately — see covid symptoms in children.

This content is informational and does not replace a medical consultation, diagnosis, or treatment.