Scrotum

The scrotum is a pouch of skin and muscle below the penis. It contains the testicles, also called testes, along with the epididymides, blood vessels, nerves, and parts of the spermatic cords.

The testicles make sperm and the hormone testosterone. The epididymis is a soft, coiled tube behind each testicle where sperm mature and are stored. Each spermatic cord connects a testicle to structures inside the lower abdomen. It carries the blood supply, nerves, and the tube that transports sperm.

A seam called the scrotal raphe runs down the middle of the scrotum. Inside, a wall separates the two testicles. It is common for one testicle—usually the left—to hang lower than the other.

The scrotum is a body part, not a disease or diagnosis. Its size, skin colour, wrinkles, and position can differ between people and can change with temperature, movement, and sexual arousal.

Sperm production works best at a temperature slightly below the body’s internal temperature. The scrotum helps maintain this cooler environment by moving the testicles closer to or farther from the body.

Two types of muscle help with this:

• The dartos muscle wrinkles or loosens the scrotal skin
• The cremaster muscle raises or lowers each testicle

In cold conditions, these muscles pull the testicles closer to the body and tighten the skin. In warmth, the scrotum becomes looser so the testicles hang farther away. These normal changes may happen quickly.

The scrotum also offers some protection from friction and minor impacts. However, because it is outside the main body cavity, it can still be injured.

Blood vessels within the spermatic cords supply the testicles. A network of veins helps cool incoming blood before it reaches them. Nerves carry sensation and help trigger muscle movement.

Changes in the scrotum may involve its skin, the testicles, the epididymides, blood vessels, or nearby tissues. Knowing what the area usually looks and feels like can help you notice a new change.

A normal testicle usually feels smooth and firm but not rock-hard. The epididymis may feel like a soft ridge or cord at the back and top. This normal structure is sometimes mistaken for a lump.

Not every change means there is a serious problem. Temporary tightening from cold, mild unevenness, visible hair follicles, and one testicle hanging lower are common. A clinician can assess a new lump, swelling, persistent ache, or skin change when the cause is unclear.

Scrotal health can also matter during fertility care. Conditions affecting the testicles, spermatic cords, or temperature around the testicles may affect sperm production. A semen analysis is the test used to assess sperm number and movement; appearance of the scrotum alone cannot show fertility.

Several different conditions can affect structures in or around the scrotum:

• Testicular torsion happens when a testicle twists around its spermatic cord, reducing its blood supply. It often causes sudden, severe pain on one side, sometimes with swelling, nausea, vomiting, or a testicle sitting higher than usual. This is an emergency.
• Epididymitis is inflammation of the epididymis, often linked to infection. Pain and swelling may develop more gradually. Urinary symptoms, discharge, or fever can occur.
• Orchitis is inflammation of a testicle. It may be caused by a viral or bacterial infection and can occur with epididymitis.
• Hydrocele is a collection of fluid around a testicle. It commonly causes painless swelling, although a large hydrocele may feel heavy or uncomfortable.
• Varicocele means enlarged veins around a testicle. It may feel like a soft bundle of cords, usually above the testicle, and may be linked with aching or fertility concerns.
• Spermatocele is a fluid-filled cyst near the epididymis. It is usually noncancerous.
• Inguinal hernia occurs when tissue from the abdomen pushes into the groin and sometimes the scrotum. The swelling may become more noticeable when standing, coughing, or straining.
• Testicular cancer usually begins inside a testicle rather than in the scrotal skin. It may cause a painless testicular lump, firmness, enlargement, or a heavy feeling. These changes have many possible causes, but they should be examined.
• Skin conditions such as eczema, fungal infection, cysts, or irritation can affect scrotal skin. Scratching and strong skin products may make irritation worse.
• Injury can cause bruising, pain, or swelling. Significant trauma may damage a testicle or its blood supply.

Sudden severe scrotal or testicular pain needs emergency assessment, even if the pain improves. Testicular torsion cannot be ruled out at home, and treatment is time-sensitive.

Seek emergency care after a major injury if there is severe swelling, an open wound, uncontrolled bleeding, or a testicle appears displaced. A painful groin or scrotal bulge with vomiting, abdominal pain, or inability to push the bulge back also needs urgent assessment.

Pain or swelling with fever, feeling unwell, urinary symptoms, or discharge should be assessed promptly the same day.

If you have no pain, lump, swelling, injury, or other concern, there is usually nothing you need to do specifically for the scrotum. Wash the skin gently and dry it well. Avoid applying fragranced or medicated products unless there is a clear reason to use them.

There is no single appearance or position that everyone’s scrotum should have. You may choose to become familiar with what is usual for you, without repeatedly squeezing or pressing the testicles.

Arrange a routine appointment for:

• A new lump or change in testicular firmness
• Swelling that persists or keeps returning
• A continuing dull ache or heavy feeling
• A change in testicle size or shape
• A skin sore, rash, or lesion that does not settle
• Questions about fertility or development

Before an appointment, note when the change began, whether it affects one or both sides, and whether it changes with standing, coughing, exercise, or lying down. Also record any fever, urinary symptoms, discharge, injury, or recent sexual exposure. This information can help guide the assessment.

A clinician may examine the area while you are standing and lying down. A scrotal ultrasound uses sound waves to show the testicles and surrounding tissues. Doppler ultrasound can also assess blood flow. Urine tests, infection tests, blood tests, or semen analysis may be used when relevant.

Is it normal for one testicle to hang lower?

Yes. Mild unevenness is common and helps prevent the testicles from pressing directly against each other. A new or marked change should be checked.

Why does the scrotum tighten and loosen?

Its muscles respond to temperature, touch, movement, stress, and sexual arousal. Tightening in cold conditions and loosening in warmth are normal functions.

Are small bumps on the skin normal?

Hair follicles, oil glands, and small blood vessels may be visible. Do not squeeze a bump that is painful, inflamed, growing, bleeding, or otherwise changing. A clinician can examine it if it does not settle.

Should I perform regular testicular self-exams?

Routine screening recommendations differ, and evidence has not shown that formal screening benefits all people without symptoms. Being familiar with your usual anatomy may still help you notice a change. A new lump, firmness, or enlargement needs clinical assessment rather than repeated checking at home.

Can scrotal pain be diagnosed by how it feels?

No. Torsion, infection, injury, and other conditions can overlap in how they feel. Sudden severe pain requires emergency assessment rather than waiting to see whether it passes.

Does scrotal size show testosterone level or fertility?

No. Scrotal appearance alone cannot measure hormone levels or fertility. Blood tests can assess testosterone when medically appropriate, while semen analysis assesses sperm.