I had a plastic surgery in 2006 after gastric bypass in 2003. recently, i started to have pulsating or throbbing sensation on the ps scar. what is causing this?

Sounds unusual: This is not typical. A change in the scar 7 years after should be evaluated. Pulsating or throbbing suggests a vascular lesion which is very unusual.

Too general to know: Where is the scar? What surgery did you have?

Scar tissue: As the scar tissue becomes more prominent, it pulls on sensory nerves. In order to soften the scar tissue, patient must have steroid injections.

Painful Scar: There are many causes of a painful scar. The most common is just normal healing that itches and subsides rather quickly. If the pain persists it is usually due to a neuroma or an impinged or cut nerve in the area of the scar. The scar can also be tethered and cause discomfort due to its tethering and contracting on the surrounding tissue. A more rare cause is scar endometriosis.

Painful scar: The most common cause of a painful scar is a neuroma - where a sensory nerve ending gets mixed up in the scar tissue. But if it truly is "pulsating", like an artery would be - then that needs a more urgent evaluation.

See below: You may be having inflammatory changes or even a keloid scar formation, even though many years have passed. Have a ps evaluate you.