Should I worry about a sudden swollen tongue?

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Q. What would cause my tongue to suddenly swell? Could this be a possible side effect of medication, or something else?

A. There are many reasons for a swollen tongue. Indeed, a reaction to a medication is one of the more common causes. For example, a well-known side effect of ACE inhibitors (a class of drugs used to control blood pressure) is a condition called angioneurotic edema. Swelling of the face, lips, and tongue can happen quickly in people who take an ACE inhibitor. The reaction may occur soon after it's first taken or at any time thereafter. Sometimes people get this reaction even though they have used the drug for several years. ACE inhibitors are more likely to cause angioneurotic edema in African Americans.