Is semen blood?

Patient's question:

Hello, I had sexual intercourse with my wife yesterday and found that the semen I released was red. It scared me at the time. I want to ask, is this semen blood? What's going on? Is it serious? Thank you, doctor

Doctor's answer:

Semen suddenly changes from its normal creamy white color to blood-red, brownish-red, or mixed with blood streaks, of course containing blood. So where does the blood come from? It is undoubtedly due to a pathological condition in some part of the spermatic pathway, such as bleeding, inflammation, or even a tumor. Do not take hematospermia lightly, as it could also be a sign of a serious disease. It is best to consult a specialist doctor for a thorough examination.
Clinically, hematospermia is not uncommon. After detailed clinical and laboratory tests, the majority can be controlled or cured through treatment, while only a very small number of tumor patients require further treatment.
The composition of semen consists mainly of the small volume of sperm, with the majority coming from the seminal vesicles, followed by the prostate. Anatomically, the ejaculatory ducts connecting the seminal vesicles open into the posterior urethral crest of the posterior urethra, surrounded by 10–20 openings of prostatic ducts. In fact, the seminal vesicles, prostate, and posterior urethra are interconnected, making it easy for inflammation to spread from one to the others. Additionally, the wall of the seminal vesicle is very thin, and once congested, the blood-filled wall is prone to bleeding. Therefore, the most common causes of hematospermia are first seminal vesiculitis, followed by prostatitis and posterior urethritis or congestion of the posterior urethra. It can also be caused by inflammation spreading from nearby organs, leading to inflammation, swelling, congestion, and bleeding of the seminal vesicle wall.
Generally, at least 70% of hematospermia cases in individuals under 30 are caused by inflammation.