HSG stands for HYSTERO SALPINGO-GRAPHY. It is a test to know the patency of the fallopian tubes. It is done by injecting a dye in the uterus through cervix by inserting a cannula under screening and taking X-RAYS. In normal patent tubes the dye should freely move from uterus to fallopian tubes and should be seen in the peritoneal cavity i.e. abdomen. If we don’t see the dye in the tubes then it shows that tubes are blocked.