Haematospermia (or hemospermia) is the presence of blood in sperm. It may be due to an injury to the penis or prostate gland (eg. falling astride a bar), excessively athletic sexual intercourse, prostate gland cancer or infection (prostatitis), seminal vesciculitis (infection of the seminal vesicles), an abnormal bleeding tendency (eg. haemophilia) or medications that may cause bleeding (eg. warfarin). In many cases, no specific cause is found and the problem settles spontaneously.