Why does it swell under your tongue after eating certain foods?

Swelling under the tongue after eating certain foods can be a reaction to allergens, particularly in cases of oral allergy syndrome. This occurs when the immune system mistakenly identifies proteins in certain foods, like fruits or nuts, as harmful, leading to localized swelling and irritation. Additionally, acidic or spicy foods may also cause temporary inflammation due to their irritating properties. If swelling is persistent or accompanied by other symptoms, it's advisable to seek medical advice.