What causes a pulsating feeling in the lower abdomen and pressure feeling?

The most common cause of a pulsating sensation in the abdomen is the beating of the largest artery in the body,the aorta. It is more noticeable in slender individuals but high blood pressure and presence of an aneurysm must be ruled out when strong pulsations are felt. However a pressure discomfort isn't normal. I recommend having a physician examine&advise you if symptoms persist.