sick betta?!

Question
hi, i have a betta fish that is about 2 years old, he lives in a large bowl and i change his water about every 2 weeks. i feed him a small amount of flakes mixed with blood worms twice a day.  He has always been very healthy and active, however, about a month ago i noticed a very small lump on the middle of his left side.  I didn't think much of it at the time but now it has gotten larger and he seems sort of puffed up around his gills. he also seems to be a little less active.  do u have any idea of what could be wrong with him or what i can do to help him?
Any advice would be greatly appreciated.
-thank you

Answer
Hello Zoe-

Unfortunately, this lump could be a tumor or a cyst. Both are very common in bettas nowadays, though some are not fatal. Your betta may decide to "scrape" the lump off, in which case he will develop a scab (treat with Melafix daily and add a dose of aquarium salt to promote healing if this occurs.)

The lump may also be internal swelling (ex. a swim bladder disorder) but you would usually see a change in the fish's ability to swim right-side up. A dose of salt should bring down the swelling, if it is caused by fluid build-up.

Most lumps, however, are tumors or cysts, and there really isn't much to do, besides treating any symptoms that occur.

Hope this is helpful!
-Amber Worman