What is COVID-19?
COVID-19 is the disease caused by the coronavirus SARS-CoV-2. The disease can cause respiratory symptoms and fever, and in severe cases it leads to breathing problems. The virus is spread by coughing, sneezing, singing, talking and so on. During activities that produce droplets, the virus is released into the air. If other people inhale those droplets, or get them in their mouth, nose or eyes, for example via their hands, they may become infected with the virus.
If you infect someone, it takes 1 to 14 days before that person might develop any symptoms. This is called the incubation period. The incubation period for the Omicron sub-variants is usually 3 to 4 days.
Possible symptoms of COVID-19:
- Cold symptoms (such as a nasal cold, runny nose, sneezing, sore throat)
- Shortness of breath
- Elevated temperature or fever
- Sudden loss of smell and/or taste (without nasal congestion)
Symptoms may also include:
- General aches and pains
- Muscle aches
- Abdominal pain
- Weight loss / loss of appetite
- Eye pain
- Eye infection (conjunctivitis)
- Various skin abnormalities (such as a rash)
- Feeling unwell
What to do if you have symptoms?
If you have symptoms that could indicate COVID-19, you no longer have to use a self-test. It is important to avoid transmitting a possible infection to others, especially people in vulnerable health. For that reason, follow these recommendations if you have symptoms.
People who are older, have underlying health conditions, or have impaired immunity have an increased risk of becoming seriously ill, especially if they have not been vaccinated or had a previous SARS-CoV-2 infection. A detailed description is provided on the RIVM page about COVID-19 risk groups. This page also presents additional recommendations to prevent infection.
Recovery after illness
The amount of time it takes to recover from COVID-19 can vary from person to person. Some people only have cold symptoms and recover within a few days, but there have also been people who had persistent symptoms for a long time, extending many weeks. People with COVID-19 who have been admitted to hospital generally need more time to recover. This depends, among other things, on whether they are healthy other than the coronavirus infection.
Some people have long-term symptoms after a SARS-CoV-2 infection. This is referred to as ‘Long COVID’ or ‘PASC’: Post-Acute Sequelae of SARS-CoV-2. These symptoms may persist for several weeks after COVID-19, and could sometimes last for months. Read more about Long COVID.
Infected more than once
People who become reinfected generally seem to become less seriously ill, but can still pass the virus to others. Most people build up immunity to the virus after infection. It is not yet certain how long you will be protected and how effective that protection is against different variants of the virus.
Vaccination prevents you from becoming seriously ill from an infection with the coronavirus SARS-CoV-2. If you have been vaccinated, you can still become infected. However, you are less likely to be contagious than if you had not been vaccinated.
Flu and COVID-19
What are the most important similarities and differences between flu and COVID-19? See the FAQs about flu and COVID.
There are many different types of viruses, including a family known as the ‘coronaviruses’. Examples include the coronavirus that causes Middle East Respiratory Syndrome (MERS-CoV) and the coronavirus that causes Severe Acute Respiratory Syndrome (SARS-CoV1) and was the virus behind the SARS epidemic in 2003. The coronavirus that causes COVID-19 is officially called SARS-CoV-2. There are different variants of the SARS-CoV-2 virus, such as the Delta variant and the Omicron variant.
For more information about the different variants and related research, see the RIVM page about the SARS-CoV-2 variants.