Can you paint over wood cabinets?

We have old wood cabinets, though I don’t know the wood type. They’re stained a medium brown color, and presumably varnished, though it’s low gloss and not very noticeable. The cabinets are at least 20 years old, but we can’t afford to replace them right now.

What can we do to paint them? Do we need to strip them first or just sand?

Yes, but I would recommend to sand it down first

Yes you can. Bring a door to your local Benjamin Moore Paint company. They will be able to tell the finish on the wood and will tell you to either sand them, or de-gloss them and then place a primer
base coat to receive the new paint.

As per advice from our local Ben Moore store: Paint Stix primer first and finish coat in Advance.
The Stix primer will stick to anything: glass, poly, tile, formica. Its a great product and will not come off.
Then add a finish coat of Ben Moore Advance Interior Paint. It dries to a hard finish for cabinets use.
You will end up with a professional looking job that will last.

Yes you absolutely can. It is a lot of work but can transform your space potentially. You must sand the doors all the way down. I would use an 80 grit pad on an orbital sander to rip down the old finish. 200 grit paper will clean up all the damage from removing the stain. Before you paint wipe down the doors with a damp rag and allow to dry before painting.

Yes you can! I would sand them down first and then apply a basecoat before painting. Remember, the glossier the paint, the easier they are to wipe down.