Ich, there are medicines you can get, but if you heat the tank up to 86 degrees for 2 weeks. Make sure you raise the temp slowly so you don't shock the betta.
SBD~ one of the causes is constipation, so treat for that and see if the SBD resolves. To treat for constipation feed frozen daphnia, then fast the fish. You can also do an epsom salt bath, leave the fish in the bath, do not use the bath for more then 10 days and make sure to do 100% water changes every day. If it's a damaged swim bladder I don't think there's much that can be done besides lowering the water level so the fish can easily reach the surface of the water.
Fungus~ Sometimes AQ salt baths will help, but I think my fish had it too bad. I ended up using a medicine that treated fungal infection, wish I had used it first.
Fin Rot~ Depends on how bad it is. Sometimes keeping the water very clean, using AQ salt, and using Seachem Stress Guard will work if the rot is caught early enough. If it isn't then medicine to treat the rot will be needed.
Dropsy~ it's usually a symptom of a bigger problem like organ failure. About the only treatment I know that might work is epsom salt baths, but it's a long shot.
Popeye~ epsom salt baths.