Swelling of the tongue can occur due to inflammation of the tongue (known as glossitis), the presence of abnormal substances (such as amyloid protein) in the tongue, the collection of fluid in the tongue as a result of different disease processes, or tumors that infiltrate the tissues of the tongue. An enlarged or swollen tongue can also occur as an allergic reaction to medications or other substances. In this case, the swelling is due to fluid accumulation in the tissues of the tongue, medically known as angioedema. A dramatically swollen tongue can lead to breathing problems and may be a medical emergency. Treatment of allergic reactions that include swollen tongue can include epinephrine, antihistamines, and/or steroid medications.