Penile hardness requires physical examination, blood and biochemical tests such as hormone levels, color Doppler examination of the corpus cavernosum of the penis, and nocturnal erection test and other tests. 1. Physical examination: first of all, it is necessary to carry out physical examination, mainly to check whether there are traumas, penile deformities and other abnormalities, as well as hypospadias and other conditions exist. 2. Biochemical examination: It mainly includes sex hormone test, triglyceride, cholesterol, blood sugar test, etc., to exclude whether there are endocrine diseases leading to erectile dysfunction. 3. Color Doppler examination of penile corpus cavernosum: through ultrasound Doppler examination to clarify whether there is insufficient blood supply to the penile corpus cavernosum and venous fistulae and other vascular pathologies leading to erectile dysfunction. 4. If necessary, nocturnal erection test is needed to identify organic and psychological erectile dysfunction. There are many reasons why the penis cannot get hard, if symptoms occur, it is recommended to actively seek medical attention.