My 16 week old is teething & drooling a lot and has had a stuffy nose/slight cough for 2 days. could these be related?

No. Nasal congestion: & cough are symptoms of a viral upper respiratory illness. Teething does not cause fever, diarrhea or any other symptoms not related to the gums , although some babies have pain & irritability. Drooling at 4 months does not necessarily mean a baby is teething, just that the salivary glands are beginning to function. The central lower incisors usually erupt first, around 6 months.

Irritant effects: The first months are troubled by narrow nasal passages & exposure to dust, fragrences, smoke & other irritants.Baby tries to flush these out of the nose with mucous but this often ends as congestion & produces rattling with breathing. The best rx is washing out the nose with saline & suctioning the remainder. Eliminate irritants from babies environment & this will happen less.