A:

It is not unusual for a man to notice blood in the semen when he ejaculates. Doctors call this hematospermia. There are several reasons why this might happen. But quite often, no specific reason is found.

Here are possible sources for blood in the semen:

• Prostate or bladder infection
• An enlarged prostate (benign prostatic hyperplasia or BPH)
• Surgical procedures such as a prostate biopsy or cystoscopy (bladder scope procedure)
• Trauma to the testicles or prostate, which might happen after horseback riding or riding a bicycle
• Very frequent masturbation

In older men that notice bloody semen often, cancer is a concern.

You should see your doctor if the problem keeps happening for more than three weeks. See your doctor sooner if you have any of these other symptoms:

• Pain when you ejaculate
• Pain when you urinate
• Fever
• Pain, tenderness or swelling in the genital area
• Low back pain

These symptoms would suggest an infection or rarely, an abnormal growth or tumor.