Hello and welcome to e health forum.
The cause of respiratory infections can either be a viral or due to bacterial origin.
Most Viral infections or the upper respiratory tract are usually benign, and subside within 7 to 10 days with conservative management with anti-inflammatory medications like advil or motrin. Cough and throat irritation can be reduced with cough lozenges and vitamin C supplements.
But in case of bacterial infections, antibiotics will be very important for complete recovery.
With proper and effective treatment most infections usually subside without any long term residual effects.
You may consult with your treating doctors, who can prescribe you the proper treatment.