Matter from (sinus?) blocks air passage back throat forced to cough up vs. choke - no mucus, infection or congestion. 1x2cm (3mm thick) - what r pos.?

Allergy bs dryness : You could have allergies or it even sounds more likely that you are breathing in very dry air and your nasal passages are drying out and you are crusting way up inside. When they loosen up when you awaken you swallow them and cough them out. Put a cool mist humidifier in your bedroom and get checked by an ENT to be sure there is nothing else wrong.