Bacterial sinus infections (also known as sinusitis) frequently occur after a viral infection such as a cold or flu. The infection is classified based on how long the symptoms last. The classifications are acute, subacute, chronic, and recurrent.
Facial pressure occurs from the build-up of mucus in the sinus cavities. The pressure can be limited to the sinuses in the cheeks or include the sinus in the forehead.
Nasal discharge is generally present with a cold or flu. However, in a sinus infection, it is thicker and yellow or green in colour.
Doctors call the sinus infection after a cold a double sickening. That's because the patient almost feels better before starting to feel sick again. If you have been sick for more than ten days--or your symptoms started getting worse five to seven days after the start of the cold--you may have a sinus infection.
Halitosis or bad breath from the infection may not be much of a problem since many people with sinus infections also experience a loss of the sense of smell.
The pressure from the build-up of mucus in the sinuses can also cause the teeth in the upper jaw to hurt.
Other symptoms of a sinus infection include fever; headache, persistent cough; ear pain, pressure, or fullness; eyes may be red, bulging, or painful; and fatigue.