My bottom lip was quiet swollen yesterday, the swelling reduced a little however a blister like thing has formed.?

Watch it: were you stung by something? if it is getting better, use cold compress as needed and it will resolve on its own. you can take diphenhydramine/benadryl if needed. if it happens again, i would see a doctor. also, blood pressure med like lisinopril and other meds can cause similar thing called angioedema, although yiu wouldn‘t have blister. if your tongue and throat also swell, it is emergency

Herpes: This is a viral disease that breaks out in uncomfortable blisters. Often associated with stress. The virus may be dormant but chronic an breakouts are intermittent. Try Blistex or similar. As your local pharmacist for help.