How long is a person with cold infectious?

The length of time that a person is infectious with the common cold can vary depending on the individual and the specific virus that is causing the cold. However, generally, a person can be infectious from the day they start to feel symptoms until about 2-3 days after the symptoms have gone away. Symptoms of the common cold typically include a runny nose, congestion, sore throat, and coughing.

For the first few days of the illness, viral shedding (the release of the virus from the body) is relatively low. This means that the person is not as likely to spread the infection to others. However, as symptoms peak, viral shedding increases and the person becomes more infectious. After symptoms start to improve, viral shedding gradually decreases until it eventually stops.

It's important to practice good hygiene, such as washing hands frequently and covering coughs and sneezes, to help prevent the spread of the common cold.