You are having angioedema
attacks of the lips that could be due to several reasons:
1. drug-induced: have you recently taken any drug after which this started or are you on continuous medication like blood pressure lowering drugs such as ramipril, enalapril
2. is there a history of tummy pain or facial swelling? - then you would extensive evaluation if all these occur together
3. or this could be an allergic episode - are there any existing allergies such as dust mite, pollens, insects etc?
4. the last option is idiopathic - which responds very well to long acting antihistamines such as cetirizine
10mg or fexofenadine
is good but a short acting and weaker antihistamine.