Can you tell me how to know the source of my sciatic nerve pain ?

Sciatic pain causes: The majority of sciatic pain is caused by nerve irritation ,impingement and imflamation of the lumbar spinal nerves that exit the spine from the l1-s1 levels and are often associated with lumbar disc hernia tigon or other disc and or spinal pathology. Most Drs. Skilled in this area should be able to make a reasonable dx. With a detailed pt. history and physical exam, MRI and Emg are important.

Sciatica: Pain in the distribution as you suggested describes the pattern of the nerve that travels in the leg called the sciatic nerve. The sciatic nerve is not the cause of the pain source, it is the result of an irritated nerve typically in the lumbar spine (low back) which are caused by herniated disks, spinal stenosis or degenerative disc disease requiring further evaluation by a spine specialist.