My betta has been acting wierd lately .. I don't know how to describe it but he has been swimming really fast all over the place and keeps hitting himself on the stones on the tank.
Try checking the temperature. Sometimes when their tank exceeds 81 degrees F for too long they become hyperactive. Or he could just be a crazy old fish, it happens.
I'm not a Professional on Betta fish but i have owned some over the years; as far as i know Betta are strange fish and act funny a lot!! so it's probably nothing. But most of the Betta fish i have had got sick with some thing? (multiple times, with the same fish) But they always pull though and end up living for a good long time! This is just my experience, but i think hes absolutely fine.
try adding aquarium salt (1 tablespoon per 5 gallons) to prevent any infection and strengthen the immune system. a 25% water change and temperature of 80 degrees will also help.
http://bettacare101.com
Do you clean the tank and feed him properly? He/she may be acting weird because his/her habitat (maybe to small of a tank) or because of what/when your feeding him/her.
Could be unhappy with water conditions. If he is alone in the tank, and water is clear and clean. . Not sure what can be agitating him. No mirrors? Water temp?
Crazy swimming can sometimes be a sign of nitrite poisoning.
