I get little white ulcers on my tounge. they swell to a point then takes few days and they are gone. they are painfull. what are these bumps? cause?

Many possible causes: Go see a doctor to evaluate what is going on. It could be just a disease that causes ulcers requiring symptomatic treatment of the ulcers along (like behcet's) or an infection like candida or herpes or the initial signs of something worse, like oral cancer; although cancer does not resolve. This sounds more like benign apthous uclers.

Canker Sore: Canker sores are a common form of mouth ulcer that are painful and typically seen on the tongue, inside of the cheek, lips, etc. In many cases the cause is unknown and they go away in a few days without treatment. They can be triggered by stress, foods, hormonal changes, and vitamin deficiencies. You may want to follow up with your physician to make sure they are not something more severe.

Ulcers or blisters: Ulcers are shallow and resemble little craters. They usually don't swell - if these are ulcers... These are likely aphthous ulcers. We think these are related to a viral infection. They are very common and usually occur a single lesions but sometimes (but not usually) as multiple. Blisters are "clear-like" bumps and would be more commonly associated with "swelling.".