I have lipoma benign on neck side. It causes movement, dizziness, fainting. Does it block blood circulation of vessel of neck side?

Probably not. While lipomas can be deep, and are sometimes intertwined with muscle fibers, they earle if ever go deep enough to block blood vessels, especially in the neck. It is also unlikely to be the source of your dizziness and fainting. See a general surgeon for a consultation tonfindnout for sure. Also see your primary care provider to see if any tests are needed to sort out your fainting (syncope). .