Presbyphagia is usually due to the characteristic changes produced in the structures and organs involved in the process of swallowing food. Some of these changes includes:
- Chewing problems due to loss of teeth or poor fitting dentures, which reduces the effectiveness of swallowing since food cannot be completely crushed to form a compact or homogeneous food bolus.
- Decreased saliva production, making it difficult to lubricate food and aid bolus formation.
- Loss of strength and mobility in the tongue when forming the bolus and/ or pushing the bolus to the back of the mouth.
- Slow closure of the epiglottis, which is located in the throat and is in charge of preventing the ingested food from passing into the lung.
- Decreased strength of the throat muscles responsible for driving the bolus forward. This may explain why older people sometimes require multiple swallows to move the bolus.