Diane

post photo pls, it is not easy to diagnose ailment without seeing the patient :)

That said, it is usually sign of insufficient light. But we need to see what cactus you have to be sure.

Thank you and I am sorry I took a photo but forgot to attach it..

Does anyone know the name of this cactus?

Much, much more light. Unfortunately it will always be mis-shapen.

Thank you socks. Do you know the name of this cactus?

I'm no good at identifying, but it might be difficult to ID since it's not its normal shape. Are you able to move it to a location where it will get sun most of the day?

Now that weather getting, maybe I put outside during day. What temperature outside good?

Again I don’t know. What is your lowest daytime temp?