Overview of your testicles & scrotum
Mō ō raho me pūkoro raho
Your testicles (sometimes called gonads) are two small oval-shaped organs. They hang down behind your penis, in a sac of skin called the scrotum. The medical term for testicles is testes (one testicle is a testis).
Your testicles are both about the same size. But it's normal for one to be slightly bigger than the other and for one to hang a bit lower than the other. They should feel smooth and firm but not hard without any lumps or bumps.
When you're around 11 to 12, your testicles start growing bigger. This continues until you reach early adulthood.
Your testicles produce and store sperm. They also produce the male sex hormone testosterone.
Your testicles are the main organ of the male reproductive system. They control male characteristics such as body and facial hair, sex drive (libido), muscle development, stamina and a deep voice.
Sperm from each testicle is stored in a structure called the epididymis. The epididymis sits at the top and back of each testicle. The epididymis is attached to your spermatic cord, which helps to support your testes in your scrotum. The spermatic cord runs from your testicle, through your groin to your abdominal cavity.
In your spermatic cord is another tube called the vas deferens. Your vas deferens carries sperm to your prostate gland. Your prostate produces a fluid that mixes with your sperm to produce semen which is ejaculated through your penis.
Written by HealthInfo clinical advisers. Last reviewed April 2023.
Sources
The information in this section comes from the following sources, some of which may be clinically complex or not available to the general public
Cancer Council Victoria – Understanding testicular cancer. Retrieved April 2016.
Canterbury Community HealthPathways – Scrotal lumps in adults. Retrieved January 2019.
NHS – Testicular cancer diagnosis (https://www.nhs.uk/conditions/testicular-cancer/diagnosis/). Retrieved January 2019.
NHS – Undescended testicles. Retrieved February 2019.
NHS – What Should My Testicles Look and Feel Like? (https://www.nhs.uk/common-health-questions/mens-health/what-should-my-testicles-look-and-feel-like/). Retrieved January 2019.
Orchid – Testicular cancer (https://orchid-cancer.org.uk/testicular-cancer-3-2/). Retrieved January 2019.
Patient.info – Epididymal cyst. Retrieved April 2016.
Patient.info– Hydrocele in adults. Retrieved April 2016.
Patient.info – Torsion of the testis. Retrieved April 2016.
Patient.info – Varicocele. Retrieved April 2016.
Image and embedded video sources
Epididymal cyst illustration from Shutterstock (image ID 1860701749). April 2023.
How to examine your testicles video from Prostate Cancer Foundation NZ on Vimeo.
Hydrocele illustration from Shutterstock (image ID 1861028659). April 2023.
Image of thoughtful young man from Shutterstock (image ID 90697366). December 2015.
Inflammation of the epididymis illustration from Shutterstock (image ID 1860694498). April 2023.
Male sex organs illustration from Shutterstock (image ID 265101782). December 2015.
Twisting of the testicle illustration from Shutterstock (image ID 1869893170). April 2023.
Varicocele illustration from Shutterstock (image ID 1862537458). April 2023.
Page reference: 227754
Review key: HITSP-26704
