The penis is always hard may be a normal physiological phenomenon, or it may be related to pathological factors such as circumcision, abnormal androgen secretion disease, abnormal penile erection, inflammation of the urinary system and so on. 1. Normal physiological phenomenon If young men are more sensitive to the role of androgens by sexual stimulation can easily cause brain excitement, nerve conduction caused by rapid congestion of the cavernous arteries of the penis, the penis can appear always hard symptoms, this phenomenon is usually normal, no need for special treatment. 2. Pathological factors (1) circumcision: the long foreskin or prepuce, easy to cause the coronal groove and the inner plate of the foreskin and other parts of the foreskin scale caused by bacterial growth, these substances repeatedly on the penis glans to produce stimulation is easy to cause sensitivity, the penis is always hard symptoms. (2) Androgen abnormal secretion disease: such as testicular mesenchymal cell tumor, adrenal cortex growth can cause androgen secretion abnormality, thus causing the symptoms of penis always hard. (3) Abnormal penile erection: it refers to the persistent abnormal penile erection without sexual stimulation, often for more than 4 hours, which can be divided into ischemic and non-ischemic, and need to go to the hospital in time for diagnosis and treatment. (4) Inflammation of the urinary system: such as prostatitis, glans inflammation and so on may produce inflammatory stimulation to the penis, and may appear always hard symptoms. Always hard penis is not limited to the above diseases, so when the symptoms of always hard penis appear, it is recommended to go to the hospital in time, find out the cause and actively cooperate with the treatment, so as not to delay the condition.