How can I tell the difference between a sinus infection and a bad col? I also have a history of pneumonia and bronchitis

Snot, pain, temp CMD. Cold can cause fever, headache, stuffy nose, clear to light colored discharge. Sinus infection more likely days into a cold; often with face or dental pain (often 1 sided), thicker, yellow/green nasal discharge. Both can have cough, ear pain/discomfort, ear symptoms, vertigo. Sinus often after cold, improvement, then worsening again. Plane travel, scuba risk. Given pulm hx: call ur doc.
Cold versus Sinus. The difference between an cold and a sinus infection is how long the symptoms last. A cold generally lasts 3 - 7 days. If "cold" symptoms persist beyond ten days, that's likely sinusitis. Most episodes of sinusitis follow the common viral upper respiratory infection, a cold. Symptoms longer than ten day, go see your doctor.