My left big toe feels numb on the inside next to the second toe. i have sciatica on that side as well. related?

Very likely: Nerve impingement (anywhere from the spine all the way down the leg) can cause those symptoms. See a physiatrist to confirm the diagnosis and to come up with a treatment plan.

Yes: This is the classic sensory distribution of the L5 netve root compression of which csn give you buitocks psin to leg and numbness to toes.

Yes: If you have sciatica it can without question effect the big toe.

Yes It is Related: If the numbness is new, it could mean your sciatica is getting worse. If the numbness doesn't resolve in a few days, I would suggest seeing a spine/pain specialist to discuss your options. If MRI not done, it may be something to consider if numbness persists or increases.