Under my tongue i had an ulcer, now it has swollen a bit and i don't know what it is?

Lesion: It is a lesion of some sort, but more info is needed.. What it looks like, how long it has been there, your social habits, med history, etc, etc. These things usually resolve by themselves, without treatment, in 10 to 14 days. If the lesion is there for more than two weeks, please see your physician or dentist. Feel better soon.

It could just be a: Canker sore/apthous ulcer. Try using otc topical orabase or orajel cteam.Follow up with ur dr if it gets worse. Take care! http://www.Healthline.Com/health/mouth-sores.

Could be: Could be anything from a traumatic injury (such as a scratch from a crust of bred) to an ulcer to a blocked salivary gland duct, to oral cancer. You have to be seen to be diagnosed. Can't do this over the computer. Please call your dentist for an examination.