How can being overweight impact sciatica?

Obesity and sciatica: Think of the disc as a marshmallow. More weight on it causes it to compress down and swell out more. That outward pressure is what causes most of the nerve pressure that generates sciatica. A dramatic weight change is not necessary, just a few pounds may make a big difference in symptoms. Especially if coupled with mckenzie pt and some medical direction.

Yes: More weight = more stress on the bones and discs of the spine resulting in more pain issues.