Hemospermia is one of the diseases of the male reproductive system. Hemospermia is a disease in which blood is mixed in the semen. Depending on the amount of blood contained, it may appear as naked-eye hematosperm, clots containing blood, or only a small amount of red blood cells under the microscope to determine the nature and severity of the lesion. Red semen ejaculated during sexual intercourse is mostly seen in modern medicine as seminal vesiculitis, which is less common clinically. The disease is often complicated with prostatitis, and the route of infection is mostly direct spread of urethral and prostate infection; followed by lymphatic and bloodstream infections. The invasion of bacteria and the stimulation of inflammation cause the seminal vesicles to become congested, and when sexual intercourse occurs, the smooth muscle and blood vessels contract, resulting in a large number of red blood cells and pus cells in the seminal fluid. According to Chinese medicine, hematosperm is mostly due to the patient’s kidney yin deficiency, the phase fire is exuberant, forcing the blood to travel; or due to excessive intercourse, the blood ligaments are damaged, and the blood flows with the semen; or due to the downward injection of damp heat, fumigating the seminal chamber, and the blood heat travels delicately. Generally speaking, blood sperm is not easy for people to notice immediately, unless there is more bleeding, otherwise it is more difficult to be found during sexual intercourse. Even if the penis and clothing are found to be bloodstained after intercourse, people tend to first think that it is the woman’s fault. If you wear a condom during intercourse or ejaculate in vitro, it is not difficult to detect bloody semen. When semen suddenly turns from its normal milky white color to blood red, reddish brown or mixed with blood, of course, blood is mixed in. So where does the blood come from? It’s just a lesion in one of the tissue parts of the sperm pathway, such as bleeding, inflammation, or even a tumor. Don’t take hematosperm lightly, it can also be a sign of a serious disease, it is best to see a specialist for serious examination. Clinically, hematospermia is not uncommon, and after detailed clinical and laboratory examinations, most of them can be clearly diagnosed and controlled or cured, while only a very small number of tumor patients need further treatment. Since semen is composed of components other than spermatozoa of very small volume, it mainly comes from the seminal vesicle gland, followed by the prostate gland. Anatomically, the ejaculatory duct connecting the seminal vesicle gland opens at the urethral crest of the posterior urethra and is surrounded by 10-20 prostatic glandular openings. In fact, the seminal vesicle gland, prostate gland and posterior urethra are in communication with each other and inflammation can easily spread from one of them to the other two. In addition, the wall of the seminal vesicle gland is very thin, and once it is congested, the vascularized vesicle wall can bleed easily. Therefore, the most common cause of hematospermia is firstly vesicourethritis, followed by prostatitis and posterior urethritis or posterior urethral congestion. Inflammation, swelling, congestion and bleeding of the wall of the seminal vesicle gland can also be caused by the spread of inflammation in other adjacent organs. Generally, at least 70% of hematospermia under the age of 30 is caused by inflammation. The appearance of hematosperm differs due to the site of bleeding and the amount of blood: blood from the mucous membrane of the urethra, which is congested during erection, is bright red and does not mix with semen, resembling mixed blood. Hemosperm caused by various inflammatory and traumatic conditions is well mixed and reddish to coffee colored, which is due to a change in color of blood stored for a longer period of time. Since the semen accumulated in the seminal vesicle gland cannot be emptied in a single ejaculation, even if it is treated promptly and adequately, the hemorrhagic semen will last for some time before it disappears. Due to the complex anatomy of the seminal vesicle gland, prostate gland and vas deferens and ejaculatory ducts, poor drainage can easily turn chronic, thus causing secondary vas deferens obstruction and edema obstruction at the mouth of the ejaculatory ducts, resulting in dry ejaculation with only ejaculatory action but no semen discharge. This is the mechanism by which hematosperm causes infertility. Other causes of infertility include changes in the composition of seminal plasma during seminal vesicle adenitis, where bacteria eat nutrients in the seminal plasma, compete for oxygen, and discharge toxins and metabolites, undoubtedly exposing sperm to an extremely unfavorable environment and decreasing fertility; the increase in acidity of seminal plasma during inflammation causes the pH of seminal fluid to drop from the usual alkaline 7.2-8.9, which is suitable for sperm survival, to the minimum sperm survival requirement of 6- 6.5. In the case of inflammation, because of the presence of a large number of cells and white blood cells in the seminal plasma, which may also be interspersed with pus, the viscosity increases significantly, and the ejaculated semen is not easily liquefied, so that the sperm cannot move and cannot drive straight into the cervix. The volume of sperm plasma is too little for sperm survival when inflammation is present; too much for sperm dilution is also not conducive to fertility. Of course, these analyses are only superficial, in fact, many links or causes are not clear and still need to be studied and explored, because many patients with mild inflammation do not affect fertility. Of course, if the ejaculatory ducts are blocked for a long time, there is the possibility that anti-sperm antibodies are produced in the body, as in the case of vasectomy, which further complicates the problem. Seminal vesiculitis can present with hematospermia and recurrent episodes, with about half of patients experiencing recurrence. Due to the deep location of these organs and the fact that they are ducts that transport sperm and are involved in reproduction, antibiotic treatment is often ineffective. The current clinical application of seminal vesicle microscopy is a better treatment to solve hematospermia, with the advantages of fast treatment and good results.