Viruses are notorious for causing nasal congestion (and runny noses), and hence, inflammation of the sinuses.
[quickanddirtytips.com]
Importantly, in viral URIs, nasal congestion and cough improve toward the end of the illness. 1,3 Persistent illness.
[mdedge.com]
This condition often occurs with rhinitis (inflammation of the lining of the nose), and symptoms can include nasal congestion, runny nose, nasal pressure, headache, fever,
[medicinenet.com]