I have a red patch (erythroplakia) in my mouth but it does not hurt. Is that all right?

Even without pain it should not be left alone. A red patch (erythroplakia) in the mouth is known to be more likely to progress to cancer than a white patch (leukoplakia), so among oral mucosal lesions it deserves particular attention. Oral cancer often causes no pain early on, so it is common for people to dismiss it because it does not hurt and to be diagnosed late. You should hurry all the more if 1) it lasts more than 2 weeks, 2) it keeps growing, or 3) the surface becomes rough and bleeds. We can check it at the clinic first and refer you to a university hospital for a biopsy if needed, so please do not delay.