Inaccurate shading on object

Question

I am relatively new to Blender so please excuse me if this is rather amateur!

The bottom of my torus has poor surface quality, I have scaled the vertices down for a smaller (variable) tubular radius all the way around the torus and at the bottom the surface quality is awful, with inaccurate shading. Any ideas as to what is wrong and/or how I could fix this?

Thanks, itsanate

Answer 1

These look like inverted faces.

Check your Face Orientation through the Overlay menu.
They should all be pointing outwards (blue color).

You can recalculate them through:
Mesh > Normals > Recalculate Outside