How long am I contagious with COVID?

You can spread COVID-19 before symptoms begin, while you feel unwell, and sometimes after you start to recover. A person with no symptoms can also transmit the virus. Infectiousness is affected by the amount of virus present, the course of illness, immune health, and the quality of ventilation and contact with other people.

A positive test does not provide a perfect countdown to contagiousness. Persistent fatigue, loss of smell, loss of taste, or joint pain may continue after the period of greatest transmission, while a new fever or worsening cough can signal active illness and deserves caution.

Stay home and limit close contact when you have new respiratory symptoms or fever. Improve airflow, wear a well-fitting mask around others when appropriate, avoid crowded indoor spaces, and take extra care around older adults and people with weakened immunity. Follow current local guidance for returning to work, school, and normal activities.

If you test positive, note when symptoms began and whether they are improving. Ask a clinician or local health service how the current guidance applies to your setting, particularly if you live with someone medically vulnerable.

Seek emergency help for severe breathing difficulty, persistent chest pain or pressure, new confusion, inability to stay awake, or blue, grey, or very pale lips or skin. Contact a clinician promptly if symptoms worsen, you are pregnant, or your immune system is weakened.

Ask how to judge whether your illness is improving, when close contact is safer, whether you need testing again, and what precautions are sensible for people in your household.