My Betta Has Red Sacks Hanging Off Fins

I have a betta, 6 yr old, name is bubba, I noticed 2 weeks ago his fins on belly area were starting to get some red to them, now hes pure blue to start. Today when I went to feed him his monthly pea, he has a red sack now hanging from his left fin. He is well trained so I lured him to front of tank w mirror he stayed staioned enough for me to look at it and its attached to fin that has a lot red on inside and has a red ball like sack hanging. In 6 yrs never saw this. Any help with what it may be?

 

Can you post a picture please

 

Can you post a picture please

I will try he doesn't like camera and every time I try he hides in his condo like he doing now

 

What fin is it on? From what you're describing it sounds like a "blister" on the fin. It's a fluid filled bubble on the fin and no one knows why it happens. It's just a minor cosmetic issue and a cosmetic issue would not cause any harm to the fish. Pictures really would help.

 

Well it fell off sometime past hour. But his 2 fins below its gills still have red on them both bright red on the the left fin that had the sack. I never seen the red in 6 yr and that's the only area red is at on both fins under the gill area