The testicles are oval-shaped glands located within the scrotum, responsible for producing sperm and male hormones like testosterone. While natural variations in size exist, concerns about “small testicles” are common. This article explores what is considered small, its various causes, and potential implications for health and fertility.
What is Considered Small?
Medically, the average adult testicle measures 4-5 centimeters (1.5-2 inches) in length, 2-3 centimeters (0.8-1.2 inches) in width, and has a volume of 15-25 mL. Testicles significantly smaller than these ranges, such as less than 3.5 centimeters (1.4 inches) long, are considered small.
A healthcare professional assesses testicular size using an orchidometer or ultrasound. Self-assessment can be misleading, so professional evaluation is recommended if there are concerns about size.
Causes of Small Testicles
Several medical conditions can lead to smaller testicles:
Kallmann syndrome: A genetic condition affecting hormone production, which can result in small testicular volume due to a lack of sexual maturation during puberty. Individuals with this syndrome often experience delayed or absent puberty and a reduced or absent sense of smell.
Klinefelter syndrome: A chromosomal condition where a male has an extra X chromosome (XXY), commonly causes small, poorly functioning testicles that produce less testosterone. Symptoms are often noticed during puberty and can include weaker muscles, less body and facial hair, and breast growth.
Orchitis: An inflammation of one or both testicles, usually due to a viral or bacterial infection, can lead to testicular atrophy, where the affected testicle shrinks and loses function. Mumps is a common viral cause of orchitis, particularly in young boys, and can result in testicular shrinkage.
Cryptorchidism (undescended testicles): Occurs when one or both testicles fail to move into the scrotum before birth. If not corrected, this condition can lead to smaller testicular size and impaired function. Surgical correction is often recommended if descent does not occur naturally by early childhood.
Varicocele: An enlargement of the veins within the scrotum that can sometimes cause the testicle it surrounds to appear smaller. This condition can affect sperm production due to increased temperature and reduced oxygen supply.
Injury or trauma: Direct damage to the testicles can result in diminished size, as it can impact testicular tissue.
Hypogonadism: A condition where the body does not produce enough testosterone or sperm. It can be primary (a problem with the testicles themselves) or secondary (a problem with brain signals to the testicles). Both types can lead to smaller testicular volume due to insufficient hormone production.
Testicular torsion: Involves the twisting of the spermatic cord, which cuts off blood supply to the testicle. If not treated promptly, the affected testicle can shrink.
Implications for Health and Fertility
Small testicular size can have several implications for health, particularly concerning hormone production and fertility. The testicles are the primary site for testosterone production, and a smaller volume can be associated with reduced testosterone levels, a condition known as hypogonadism. Low testosterone can manifest as decreased energy, mood changes, reduced muscle mass, lower bone density, and a diminished sex drive.
Testicular size is directly related to sperm production, as approximately 80% of a testicle’s volume consists of seminiferous tubules, which are responsible for creating sperm cells. Consequently, smaller testicles can be associated with reduced sperm density and lower sperm counts, impacting male fertility. While some individuals with smaller testicles may still be fertile, impaired function indicated by reduced size can make conception more challenging.
Small testicles can also be a symptom of an underlying medical condition that may have broader health consequences. For example, conditions like Klinefelter syndrome can increase the risk for other health issues beyond reproductive concerns. Addressing the root cause of small testicles is important for overall well-being.
When to Seek Medical Advice
Consult a healthcare professional if you notice a significant decrease in testicular size or have persistent concerns about their size. A doctor can accurately assess testicular volume and determine if there are any underlying medical conditions contributing to the size.
Seek medical advice if you are experiencing symptoms associated with low testosterone, such as unexplained fatigue, low libido, or changes in body hair. Concerns about fertility, especially if you and your partner have been trying to conceive without success, warrant a medical evaluation to assess sperm production and hormone levels. Any sudden pain, swelling, or the presence of lumps in the testicles should prompt immediate medical attention. Also consult a doctor if testicles have not descended by early childhood.