I had what you had....no fever but body aches & a ciugh that lasted a monthbeven with musinex. Yes, a virus but the flu is a virus akso, bacterial infections end up beinfmg complications of the flu. My friend is a PA & I was at her house, farmvsittjng for her ehen I got sick. She disgnosed me when they got home. Nothing like having a private physician. Lol she even made a house call for a friend & neighbor who had the same thing I did but turned into pneumonia for her. That is probably their real concern for your friend. When the immune system is low, pneumonia happens easily