Blood in the ejaculate, or "hematospermia, is symptom whose exact cause can't be found in the majority of cases. Usually the problem resolves on its own. However, in younger people various sexually transmitted diseases or acute prostatitis must first be ruled out. In older patients other conditions should be considered such as: chronic prostatitis, benign prostatic hyperplasia, prostate cancer, prostatic calculi, genital tuberculosis, and hypertension. You may consult a urologist for diagnostic examinations and to target a diagnosis.