Medications. Many cases of a swollen tongue are the result of a reaction to a medication such as an ACE inhibitor, used to treat high blood pressure, or an NSAID, or non-steroidal anti-inflammatory drug, such as aspirin, and ibuprofen. A swollen tongue due to a reaction to ACE inhibitors usually occurs during the first year of taking the medication, but can also happen after years of taking it.
Allergens. In addition to allergic reactions to medications, allergic reactions to other substances — such as foods or bee stings — can cause swelling. In food allergies and bee sting allergies, the tongue can swell, but it is less common to have a swollen tongue than it is to have a swollen throat or lips.
Infection. Another possible cause of a swollen tongue is an infection deep inside the tongue or in the floor of the mouth. This usually develops over a day or two — more slowly than the allergic type of swelling.
