How long is COVID-19 transmissible?

COVID-19 is often transmissible before symptoms and while symptoms are present, with timing varying between people. Infectiousness can last longer in some people, especially when illness is severe or the immune system is weakened.

The virus spreads mainly through particles released when an infected person breathes, talks, coughs, or sneezes. Crowded indoor spaces, poor ventilation, and close contact make spread easier. Feeling better does not instantly prove that transmission is no longer possible.

A person may spread COVID-19 without fever or other obvious symptoms. Common symptoms include cough, sore throat, tiredness, and altered smell or taste. The [COVID-19](/conditions/covid-19/) page provides broader symptom information.

Stay home when you are acutely unwell, improve ventilation, and wear a well-fitting mask when you must be near others. Avoid close contact with people at higher risk, and follow current local advice about testing and returning to normal activities.

Wash your hands after coughing or blowing your nose, avoid sharing drinks and utensils, and clean frequently touched surfaces when someone is ill. If symptoms return or worsen, reassess the situation rather than assuming the infection has ended.

Call emergency services for serious breathing trouble, ongoing chest pain or pressure, new confusion, inability to wake, or pale, grey, or blue lips or skin. Arrange prompt medical advice if illness is worsening, fluids are difficult to maintain, or you have significant medical risk.

Ask how long you should avoid close contact, whether testing can help guide precautions, when you can return to work or school, and whether your health history changes the plan.