The views expressed by me are for educational purposes only and do not establish a doctor patient relationship.
This is Dr. D.J., experienced Internal Medicine Specialist.
I am here to address your concerns and provide great service.
Prostate infection or prostatitis is the most likely cause.
Urinary tract infection also possible.
Blood in the semen can be caused by the medications as well like aspirin, plavix etc.
However, burning and presence of blood do take some importance and infection should be considered.
Prostate cancer is another possibility at your age.
Hence, an ultrasound of the prostate, urine analysis ( preferably after milking the prostate) should be considered.
Serum PSA level should be checked also.
If you are on aspirin or blood thinner medication, that should be held to see improvement.