There is no easy way to determine the blood supply to the corpus cavernosum of the penis, but it can be determined by observing the state of erection and the hardness of erection, and it is recommended to have a professional examination in a regular hospital. The main symptoms of insufficient blood supply to the corpus cavernosum include fewer or no morning erections, difficulty in getting an erection when stimulated, delayed erection during sexual intercourse, unstable erection, inability to enter the vagina, and inability to have sexual intercourse. The penis is made up of three corpus cavernosums, two penile corpus cavernosums and an elastic urethral corpus cavernosum. When there is enough blood supply in the corpus cavernosum, the penis can remain erect. If there is not enough blood supply in the corpus cavernosum, then it becomes less hard to get an erection. If you find insufficient blood supply in the corpus cavernosum, you need to seek medical attention and active treatment to avoid further development of the condition.