Influenza viruses such as H1N1 infect the cells that line your nose, throat and lungs. For adults, emergency symptoms can include: If you have emergency symptoms of the flu, get medical care right away. Some examples are asthma, emphysema, diabetes or a heart condition. But some people are at higher risk of flu complications.Ĭall your care provider if you have flu symptoms and you're pregnant or have a chronic disease. If you're generally healthy and develop flu symptoms, most people may not need to see a health care provider.

flu: Similarities and differences - Related information COVID-19 vs.