Hi.. Can understand your concern.. As per your complain it seems that you may have a mucous cyst also known as Mucocele.. It is caused due to the blockage of mucus from the salivary glands. The reason for this can be some kind of trauma like lip biting habits, lip piercing,or due to accidental damage to minor salivary gland present on lip. Many times the cysts are not harmful and heals up itself but if it does not heal itself then medical assistance is needed.. You should never pick the cyst yourself as it can lead to infections.. You should consult a doctor and doctor will do a clinical evaluation and any pathological investigation if required.. If mucocele is diagnosed there are few modalities of treatment like Laser, Cryosurgery and Corticosteroids.. But as a cyst contains a cystic lining and to prevent recurrence of cyst the cyst has to be removed surgically along with its lining as the cells of the lining can cause recurrence of the cyst.. Hope your query is solved.. Thanks and regards..