Thick semen is not always a cause for concern, especially if this consistency is infrequent. However, if semen is often very thick, it may signal a problem with the prostate or the seminal vesicles.
The consistency of semen varies from person to person. It can also change over time or even from one ejaculation to another. If a person has very thick semen, a doctor may refer to the issue as semen hyperviscosity.
If semen is very thick, the sperm cannot move as easily. As a result, it may be difficult to impregnate a partner.
In this article, we explore the causes of thick semen, describe when to see a doctor, and provide some tips for keeping the sperm healthy.
What counts as ‘thick’?
It can be difficult for a person to tell whether their semen is unusually thick. A semen analysisTrusted Source that includes a viscosity test can tell for sure.
A person may need testing and medical attention if their semen:
- seems much thicker than usual
- comes out in thick strands instead of drops
- comes out very solid or in chunks
Causes of thick semen
A 2019 review notes that around 12–29% of males have semen that clinically qualifies as thick.
Semen might become this thick due to:
Infrequent ejaculation
When a person ejaculates after not having done so for a long period, they may find an increase in the thickness and total amount of semen. Semen volume will also decrease. Anyone who feels concerned about the thickness of their semen should consider ejaculating every few days.
Dehydration
If the body is not properly hydrated, there may be less fluid in the semen, causing it to be thick or clumpy. Anyone who wonders whether the thickness of their semen results from a health issue should drink plenty of water and see whether this resolves the issue.
Infection
Leukocytospermia is a condition characterized by ejaculate with too many white blood cells — cells that typically help fight infection. It can diminish a male’s fertility. The condition can develop for no apparent reason, or it can occur when a person has an infection, such as one in the urinary tract or a sexually transmitted infection (STI).
Oxidative stress may also cause leukocytospermia. Oxidative stress commonly occurs after scrotal surgery, such as a vasectomy or following local trauma.
Additionally, with age, free radicals and reactive oxygen species may accumulate and alter the composition of sperm cells and seminal viscosity.
Usually, a doctor treats leukocytospermia with antibiotics, and antioxidants, which combat oxidative damage, may also help. Whether these interventions increase the chances of pregnancy remains unclear.
Disruption in the prostate or seminal vesicles
Semen comprises sperm from the testicles, seminal fluid from the seminal vesicles, and a small amount of fluid from the prostate. Other glands, such as the Cowper’s glands and epididymis, also contribute to semen formation, albeit in smaller amounts. The semen then travels through the ejaculatory ducts and into the urethra, where it is ejaculated.
Inflammation or problems with the functioning of either the prostate or seminal vesicles may make the semen unusually thick.
Specifically, the thickness may indicate that an issue in the seminal vesicles is causing the prostate to secrete more fluid or that the proteins that the prostate and seminal vesicles add to semen have changed. Some people may experience other symptoms of prostate problems, such as painful ejaculation, pain when urinating, or frequent urination.
What is healthy semen?
It is usually not possible to assess semen’s health by how it looks or feels. Very thick semen may reduce sperm movement or count, but many people with low sperm counts have semen that seems normal. The only way to reliably assess semen is with a professional analysis.
After a person gives a semen sample, their doctor sends it to a laboratory. The results show several measures of semen healthTrusted Source, including:
- Semen volume: This is a measure of how much semen a person produces, which should be more than 1.5 milliliters.
- Concentration: Sometimes called sperm count, this measures how highly concentrated sperm are in the semen sample. An ideal number is 39 million or higher.
- Morphology: This indicates whether the shape and appearance of the sperm are healthy. If fewer regularly shaped sperm are present in a sample, this indicates a lower chance of successful impregnation.
- Motility: This measures how many sperm can move properly. Healthy males should have motility numbers of 40% or higher.
Is clumpy sperm normal?
The clumping together of particles in a liquid is known as agglutination. Sperm agglutinationTrusted Source is not healthy and may occur due to infection, deficiencies, and sectoral trauma.
Doctors can test for agglutination as part of a semen analysisTrusted Source, with no visible agglutination deemed normal.
When to see a doctor
A person should receive medical attention if:
- Their sperm is unusually thick for more than a few days and does not respond to home care strategies, such as drinking more water.
- Other symptoms, such as painful or frequent urination or painful sex, also occur.
- They recently had sex without a barrier method with someone whose STI status was unknown or if they have not had an STI test in the last 6 months.
- They are unable to get a partner pregnant after 6–12 months of trying.
Summary
Semen consistency, volume, quality, and even color can change from day to day, and they vary naturally from person to person. Only a healthcare professional can assess whether thick semen indicates a health issue.
Anyone who notices a consistent, unexplained change in their semen should receive medical attention, especially if they are concerned about fertility or experiencing any other symptoms.
