Seminal Vesicle: What to Know

Medically Reviewed by Jabeen Begum, MD on October 04, 2022
4 min read

The seminal vesicles—sometimes called the seminal glands or vesicular glands—are part of the reproductive system in people assigned male at birth. They are small glands that produce the majority of the fluid that makes up semen, though they do not have a role in producing sperm. Sperm are produced in the testicles. 

The seminal vesicles are located inside the body, so they cannot be seen or felt by looking at or touching the penis and scrotum. They are tightly coiled and measure about two inches long when in their natural position. If you removed them and stretched them out, they would reach up to four inches in length.

Seminal vesicles play an important role in the reproductive process. Ejaculate contains a combination of fluids produced by the seminal vesicles and prostate. These fluids combine with the sperm cells that exit the penis during an orgasm

In addition to producing seminal fluid, the seminal vesicles contain muscle tissue. The muscles contract during ejaculation to push the fluid through the reproductive tract. During that process, it mixes with the sperm from the testicle and additional fluids from the prostate.

If the fluid and sperm enter a vagina, the fluid helps the sperm swim away from the penis. Sperm can then make its way into the uterus and fallopian tubes. If an ova or egg is present in the fallopian tubes, fertilization could occur, leading to a pregnancy.

The seminal fluid serves as a carrier for the sperm, and it has biological properties that enhance the chances of pregnancy. For example:

  • It contains fructose to provide energy.
  • It contains prostaglandins, which prevent the vagina from treating sperm as a foreign substance.
  • It is alkaline, which helps to counteract the acidic environment of the vagina and protect the sperm.
  • It contains clotting factors, which prolong the life of sperm.

Where Is the Seminal Vesicle Located? 

The seminal vesicles are located behind the bladder and slightly above the rectum. They are located near the tip of the vas deferens, the tube that moves sperm to the urethra before ejaculation. 

It is very uncommon to have seminal vesicle problems. Sometimes, though, they can develop infections or other conditions. You are likely to notice symptoms of these seminal vesicle problems, including:

  • Blood in the semen
  • Pain in the pelvic area 
  • Pain while ejaculating
  • Difficulty urinating 
  • Painful urination
  • Lower semen volume

Another sign that something may be wrong with your seminal vesicle is infertility. If you and your partner have trouble conceiving, that may indicate an issue with your seminal vesicles or another part of your reproductive system. You should call your doctor to discuss any unexplained infertility. You may need testing to determine the cause of the issue.

Seminal vesicle stones: Like kidney stones, seminal vesicle stones are small, solid calcifications that can form inside the vesicle. These stones can cause significant discomfort or bleeding, particularly during ejaculation. A doctor can remove the stone with a laser treatment or surgery, though. Fortunately, seminal vesicle stones are very rare.

Infections: If bacteria are trapped in the seminal vesicle, it can become infected, leading to vesiculitis or spermatocystitis. This is more common in regions where tuberculosis and schistosomiasis are prevalent. Treatment usually includes antibiotics. 

Cysts: Cysts are fluid-filled sacs that can develop nearly anywhere in the body. Cysts on the seminal vesicle can be present from birth, or they may develop later in life. It is not common to be diagnosed with cysts on the seminal vesicles, though, partly because they may cause no symptoms. They often can only be detected with imaging technology. That being said, if the cysts are large, they can cause discomfort or difficulty with urination or ejaculation. If cysts are causing unpleasant symptoms, you may need surgery to treat them.

Tumors: Tumors can develop on the seminal vesicles. It’s very rare for a seminal vesicle to be the original location for cancer, though. More often, cancer starts on another organ like the prostate or bladder and spreads to the seminal vesicles. You will need treatment from an oncologist to manage cancer anywhere in your body.

In general, diagnosing conditions of the seminal vesicles may be difficult due to their location. If your doctor suspects you have an issue with your seminal vesicle, they may order tests such as:

  • Digital rectal exam
  • Imaging (i.e., an MRI, PET scan, or CT scan)
  • Transrectal ultrasound (TRUS)
  • Urinalysis

The location of the seminal vesicles means they are naturally protected from injury or infection. Typically, lifestyle choices can keep your seminal vesicles and the rest of your reproductive organs healthy. Many experts recommend adopting healthy habits such as:

  • Avoid smoking, vaping, or other tobacco products.
  • Drinking alcohol in moderation
  • Drinking enough water
  • Eating a healthy diet
  • Exercising regularly
  • Getting enough sleep
  • Maintaining a healthy weight
  • Practicing safe sex
  • Wearing protective equipment such as an athletic cup if you participate in contact sports

Call your doctor if you are concerned about your seminal vesicles or any part of your reproductive tract. They can help you diagnose any health problems and come up with a treatment plan.