When can a simple sinus infection become something worse? took bactrim (sulfamethoxazole and trimethoprim) for 7 days, now excruciating headaches and awful smell in my nose.

Sinus Infection: Sinus infections are not always "simple". Causes can be a combination of bacteria, allergies, viruses, deviated septums, gerd, broken noses, polyps, tumors, foreign bodies, fungal infections, dental abscesses or fractures, hypothyroidism, lupus, sarcoidosis, diabetes and parasites. For more information see our website www.Nwnasalsinus.Com.

Decongestant: It is important to open the nasal passages so that pus cones out. Use a nasal decongestant.

Decongestants : Nasal decongestants can be quite addicting and can make things worse in some cases. See an ENT doc if your symptoms persist for a definitive diagnosis.

Smell concerning: The symptoms you describe are almost always the sign of something serious, especially after just completing a course of antibiotics. Consult an ENT for a thorough evaluation.