Will i need to get an x-ray if i see a doctor for a throbbing low back pain?

Yes: I would definitely x-ray your low back, pelvis, and hips. Of course along with a complete history and physical and possibly other diagnostic modalities.

See below: In general, for those who strain their backs occasionally, it is not necessary to do an xray or mri. However, if i see someone whose back is not improving after about 6 weeks, i will usually order an xray first.

Maybe: Unfortunately, xrays of the lumbar spine have a low correlation with the actual cause of the back pain. The radiation exposure is considerable and this test should be used conservatively. Mri has a higher correlation with the cause of pain. This link may be informative: http://www.Lower-back-pain-toolkit.Com/lower-back-pain-investigations.Html.

Depends: Every person with back pain presents differently. if needed the Dr. will order them.