As a note, everything has flu like symptoms which are all symptoms of the human body detecting an infection and the immunoresponse trying a battery of general remedies.

The lung and nose stuff can indicate a coronavirus or other airborne infection, but also can indicate an allergy or other trigger of the anti-dust immune systems.

Also influenza- and cold-viruses commonly have atypical symptoms (spikey fever, tinnitus, tea tastes funny, midnight insomnia, etc.) In San Francisco we’d often have multiple bugs being passed around, and signature symptoms would help indicate what you got.