Hand numbness is spine related, but probably not related to your sciatica pain.
Why this matters:
I’ve seen this question on the message boards pretty frequently. The sciatic nerve extends from the low back and down your leg. The nerves in your hand exit your spine at the neck and pass through your shoulder. How you stand can influence both the low back and neck and shoulder. If your low back is extremely arched, you’ll probably have your shoulders rounded forward, and head about 2-3 inches in front of your shoulders. If you spend a lot of time on your phone, this position can get even more intense.
If you have numbness in your hands, look at your neck, posture and shoulders. Ask yourself the same similar questions you would ask about how your sciatica pain is behaving. The clues will tell you the treatment.