Webthis combination medication is used to temporarily treat cough, stuffy nose, body aches, and other symptoms (such as fever, headache, sore throat) caused by the common. It is used to treat nose stuffiness. It is used to relieve coughing. It is used to ease pain and fever. What do i need to tell my doctor. However, it's important to be aware of the. Websep 6, 2023 · dilated blood vessels can cause nasal congestion (stuffy nose). Dayquil severe cold and flu is a combination medicine used to treat headache, fever, body.