Sebaceous Glands

Sebaceous glands are microscopic glands found in your hair follicles that secrete sebum. Sebum is an oily substance that protects your skin from drying out. Sebaceous glands can clog, so you can keep your glands healthy by following a skin care routine that includes cleansing and moisturizing your skin.


Sebaceous glands are organs full of sebum connected to your hair follicles.
Sebaceous glands are organs connected to your hair follicle that release an oily protective substance called sebum.

What are sebaceous glands?

Sebaceous glands are an organ in your skin that make and secrete sebum. Sebum is a substance that provides a protective coating for your skin to help it retain moisture. Most of your sebaceous glands connect to your hair follicles.


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What are the types of sebaceous glands?

There are two types of sebaceous glands. Both types have different locations on your body.

  • Sebaceous glands attached to your hair follicles.
  • Sebaceous glands that aren’t attached to your hair follicles.

The majority of your sebaceous glands have openings attached to your hair follicles. Some sebaceous glands work with your sweat glands and open at the surface of your skin instead of at your hair follicles. Both types perform the same function, which is to create and release sebum.


What is the function of sebaceous glands?

Sebaceous glands are responsible for producing and secreting sebum. Sebum is an oily substance made up of fat molecules (lipids) that include:

  • Cholesterol.
  • Fatty acids.
  • Glycerides.
  • Squalene.
  • Wax.


Why is sebum important for my body?

Sebum is a natural lubrication that protects your skin from:

  • Things that rub against your skin that can cause damage (friction).
  • Moisture loss or brittle hair.
  • Infections caused by bacteria or fungi.

Sebum also contributes to your body odor.

How long do my sebaceous glands produce sebum during my lifetime?

After you’re born, your sebaceous glands activate and start producing sebum. The amount of sebum your body produces is slow through childhood until you reach puberty. At the time of puberty, your body produces excessive amounts of sebum. Your sebum production reduces to normal amounts during adulthood. After age 70, your body’s sebum production slows down gradually.


Where are sebaceous glands located on my body?

Sebaceous glands develop on or near your hair follicles in the second layer of your skin (dermis). You have thousands of sebaceous glands all over your body. The only place where you don’t have sebaceous glands are on the palms of your hands and the soles of your feet. You have the most sebaceous glands on your face and scalp. Sebaceous glands that aren’t attached to your hair follicles are common on your penis, labia, lips or inside of your nose.


What do sebaceous glands look like?

If you hold a penny between your pointer finger and your thumb with the face pointing toward yours, the shape of your finger and thumb look like the outline of a sebaceous gland. The penny is the opening of the sebaceous gland, which is where your gland secrets sebum into your hair follicle. Inside the sebaceous gland are several cells that create sebum (epithelial cells).

How big are sebaceous glands?

Sebaceous glands are microscopic. To get an idea of the size of your sebaceous gland, look at a single strand of hair on your forearm. Below the surface of your skin is a tube where your hair grows. This is called your hair follicle. Inside of that tube is a tiny opening where your sebaceous gland releases sebum.

Conditions and Disorders

What are the common conditions that affect sebaceous glands?

There are several conditions that can affect the health and function of your sebaceous glands. Some of the most common include:

  • Acne: Acne is a common skin condition that causes pimples to form on your face, chest, shoulders or upper back. There are several reasons why acne forms on your skin, one of which is pores clogged with sebum (sebum plug).
  • Hyperplasia: Sebaceous hyperplasia is a harmless skin condition caused by overactive sebaceous glands.
  • Sebaceous cysts: Sebaceous cysts are lumps that grow underneath your skin. These lumps are filled with sebum fluid because they form in your sebaceous glands.
  • Sebaceous carcinoma: Sebaceous carcinoma is a rare type of cancer that starts in your skin’s sebaceous glands. This cancer causes a firm yellow lump to form on your eyelid.
  • Sebaceous filaments: Sebaceous filaments are the result of an overproduction of sebum. They cause your skin’s pores to get bigger and fill up with sebum and dead skin cells around your hair follicle. Filaments look similar to blackheads.

What are common signs or symptoms of sebaceous glands?

Although most sebaceous glands don’t have any symptoms, signs and symptoms vary for each condition and could include:

  • Pimples on your skin.
  • A red to purple bump on your skin.
  • A firm lump or bump that easily moves around underneath your skin.
  • Large pores filled with a hard, black substance.
  • A white pustule or small, fluid-filled bump on your skin where your hair grows.
  • Oily or greasy hair or skin.

What are common tests to check the health of my sebaceous glands?

A visual examination of your skin by your healthcare provider can diagnose sebaceous gland conditions, but they might offer additional tests to rule out conditions with similar symptoms or to confirm a diagnosis. Tests to check the health of your sebaceous glands include:

  • Skin biopsy: Your healthcare provider will remove a small sample of your skin to look at it under a microscope.
  • Pathology examination: Your healthcare provider will look at your removed cyst under a microscope.
  • Imaging tests like an ultrasound or a CT scan to see underneath your skin.

What are common treatments for sebaceous gland conditions?

Treatment options vary for each condition and could include:

  • Surgery to remove a cyst or cancer.
  • Taking medication (oral or topical) to help acne go away.
  • Laser or light therapy that uses bright lights to repair damaged skin.
  • Cryotherapy to freeze blemishes on your skin, which causes them to dry up and go away.


How can I keep my sebaceous glands healthy?

You can keep your sebaceous glands healthy and prevent clogging of your hair follicles and glands by using:

  • A gentle cleanser daily on your skin.
  • Skin care products that contain salicylic acid.
  • Moisturizers daily.
  • Sunscreen when you go outdoors.

You can also help your sebaceous glands stay healthy by staying hydrated and drinking plenty of water throughout the day.

Additional Common Questions

What is the difference between sebaceous glands and sweat glands?

Both sebaceous glands and sweat glands are organs in your body that protect your skin from becoming too dry. Sebaceous glands produce an oily substance called sebum and sweat glands produce a watery substance called sweat. Sweat glands have ducts, which are pathways to excrete substances to the surface of your skin. Sebaceous glands secrete sebum through your hair follicles and don’t have ducts.

Are glands in my breasts sebaceous glands?

No. The glands in your breasts are mammary glands. Mammary glands are responsible for lactation or milk production.

Do retinoids shrink sebaceous glands?

Retinoids, like tretinoin (Retin-A®), are chemicals that use vitamin A. These chemicals are found in common skin care medications to treat several conditions like acne. Studies show that using retinoids shrinks the size of your pores, but they don’t shrink the size of your sebaceous glands. Retinoids also reduce your sebaceous glands’ production of sebum.

A note from Cleveland Clinic

Sebaceous glands are an important organ for your body to keep your skin moisturized. It might be frustrating to have greasy hair or oily skin, but those are signs that your sebaceous glands are working. Follow a daily skin care routine to prevent your pores and hair follicles from clogging with excess sebum.

Medically Reviewed

Last reviewed on 12/14/2022.

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