Covid-19 can develop differently from person to person. Symptoms usually appear a few days after infection and can vary in both order and severity.
Here is an overview of how the illness typically progresses.
Symptoms appear after a few days
Symptoms of covid-19 typically occur between 2 and 14 days after contact with the virus. For many, they begin around 5 to 6 days after infection.
Most people experience mild to moderate symptoms
In the initial phase, the vast majority experience mild to moderate symptoms, which can last up to two weeks.
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The first sign
According to research, fever is the symptom that most frequently appears first. This differs from influenza, where cough more often serves as the initial symptom.
Fever is very common
A review published in PLOS One of data from nearly 25,000 adults showed that about 78 percent of people with covid-19 had a fever.
Additional symptoms may develop in the second week
After the first few days, the illness may progress with cough, sore throat, muscle aches, and headache.
Nausea and vomiting may occur early
Statistical models suggest that nausea and vomiting can occur earlier in the course of covid-19 than in similar respiratory infections such as MERS and SARS.
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Severe cases may require hospitalization
In severe cases, the illness can lead to Acute Respiratory Distress Syndrome, in which the lungs do not supply enough oxygen to the body.
Some patients require intensive care treatment around 10 days after the first symptoms appear.
Symptoms vary from person to person
The order and type of symptoms are not the same for everyone. Some may experience gastrointestinal problems before fever or cough, while others may have no symptoms at all.
Additional common symptoms
In addition to the most well-known signs, the illness can also cause chills, fatigue, loss of taste or smell, and nasal congestion.
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Signs of severe illness
Shortness of breath, confusion, chest pressure, and difficulty moving or speaking are serious symptoms that require immediate medical attention.
Different variants cause similar symptoms
Variants such as Omicron, Alpha, Beta, Gamma, and Delta generally cause the same symptoms. However, some data suggest that Delta may more closely resemble a common cold, with headache, runny nose, and sore throat.
The duration of the illness can vary
For most people, covid-19 lasts from a few days to a few weeks. However, some experience symptoms that continue for a longer period.
Long-term symptoms may occur
Long-term effects refer to symptoms that last for several weeks or months after the infection.
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According to the CDC, symptoms are considered long-term if they persist for 4 weeks or more.
How long are you contagious?
Most people can be around others again about 10 days after symptom onset or 10 days after a positive test.
People with severe symptoms or weakened immune systems may need up to 20 days of isolation.
Covid-19 and influenza are similar
Both illnesses are respiratory diseases with similar symptoms.
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However, research indicates that cough is more often the first symptom of influenza, while fever typically appears first in covid-19. Loss of taste and smell is also more common with covid-19.
When to contact a doctor
With mild to moderate symptoms, emergency treatment is not always necessary.
However, medical attention should be sought in cases of breathing difficulties, chest pain or pressure, confusion, difficulty staying awake, or discoloration of the skin, lips, or nails.
The illness usually resolves on its own
Covid-19 typically clears within 14 days. Rest, plenty of fluids, and over-the-counter pain relievers can help ease symptoms.
Sources: Medical News Today, PLOS One, and CDC.