What Is Meant by the Sudden Swelling of the Upper Lip?

By Staff WriterLast Updated Mar 31, 2020 12:48:06 AM ET

Sudden swelling of the lips is a common symptom of angioedema, an allergic reaction that is believed to be triggered by eating shellfish, exposure to animal dander and ingestion of certain medications, according to MedlinePlus. Angioedema sometimes accompanies medical conditions such as lupus and lymphoma.