Primary Causes & Pathophysiology
Oropharyngeal fault weakens tongue drive and laryngeal lift (throat closure). Poor closure lets food enter airway causing cough and aspiration (airway entry). Oesophageal blockage from stricture (scar narrowing) or tumour stops bolus (food lump) transit. Motility failure such as achalasia (tight valve with weak waves) traps food above closed sphincter (ring valve). Retained food then regurgitates (comes back) or spills to lungs.
Brain injury weakens tongue and throat lift so bolus (food lump) misdirects to airway
Nerve loss slows swallow timing and weakens closure causing cough with liquids
Missing gut nerves keep ring valve shut while waves fail so food stacks above
Chronic acid scars food-pipe wall into narrow ring blocking solids first
Tumour narrows lumen (channel) directly with rapid solids-to-liquids progression and weight loss
Allergy cells inflame wall into rings and furrows catching solid bolus in young adults