Upside down Molly

[Momdatroks]

I've had this female Molly for several months now and the last couple days she can't seem to stay upright. She will swim but always turns back upside down. I've never seen anything like it. Any advice on why this is happening?

 

[Aiken Drum]

Possibly swim bladder disease.

Can you isolate the fish, up the temperature to 28.5c/80f and not feed it for a few days? See if that works first.