Betta turned upside down

I walked past my betta, Harvey, a few minutes ago and he was upside down. As soon as he noticed me he turned over and swam away really quick.

Could something be wrong with him? Sometimes he is face down and he looks like he is looking for something in the rocks. I know this sounds crazy, but it's what it looks like.

The other day he looks like he was struggling to breathe, so I changed half of his water. I also put some aquarium salt in there.

What do you guys think? What should I do now?

Some Bettas are prone to constipation, which can lead to SBD(swim bladder desease) this causes a fish to swim upside down or sideways etc. One way you can relieve constipation in a fish is to try fasting for a few days... 1-2 days should be fine as bettas can go a long time without eating. If the betta hasn't pooed... then try a frozen pea that has been blanched in declorinated water, mash it and feed it to your betta, not too much though. A bettas belly is only about the size of its eye. Try that before anything else. This happened to my betta although not to the same degree. Also pay attention to what your bettas poo looks like. White and stringy could mean internal parasite.

As for the betta seeming hard to breath, bettas do depend on surface air to survive, but you also need to check water quality. Make sure ammonia and nitrites are zero. Ammonia can burn a fish's gills making it hard for them to breath. Frequent water changes may be nessecary.

What size is your betta's tank?
Has it been cycled?

P.S. Aquarium salt is not really nessecary in a betta tank. Could also be bad if too much is used. Good clean dechlorinated water with zero ammonia and zero nitrites is best.o