Buzzing Sensation Behind Upper Leg, Like Rhythmic Blood Pumping. Is It A Trapped Nerve?
Thanks for posting your query.
From your description, the paresthesias on the back of your leg which gets relieved on lying down is the sign of a nerve compression at the spinal level.
This could happen due to disc prolapse or stenosis of the foramina form which nerves come out from the spine.
An MRI of lumbosacral spine will help in diagnosing the extent of compression.
You may get the initial physical examination, relevant tests and treatment done under care of 'Orthopaedician'.
Treatment depends on the extent and cause of compression. Physiotherapy is the mainstay of treatment in most of the cases.
Till then avoid bending forwards and lifting heavy weights.
I hope this answers your query effectively.
In case you have additional questions or doubts, you can forward them to me, and I shall be glad to help you out.
Please accept my answer in case you do not have further queries.
Wishing you good health.
Regards.