What is the difference between a sinus infection and a cold? What are the signs?

Several. Major symptoms are infected drainage, nasal blockage, and facial discomfort. Minor symptoms are smell disturbance, facial swelling-redness-tenderness, upper dental discomfort, cough, fever. Viral and bacterial infections have the same symptoms but viral ones resolve over 10-14 days but bacterial infections either worsen over time or plateau and persist for 3-4 weeks.