What Is a Cyst?
A cyst is a closed sac or pocket under the skin filled with fluid, pus, or other material (like keratin or sebum). Most skin cysts are benign (non-cancerous) and develop slowly.
They can appear anywhere on the body, but are most common on the face, neck, scalp, back, and genitals.
There are many types of cysts—epidermoid, sebaceous, and pilar cysts being the most common ones found in adults.
Key Characteristics
Appearance: Round bump under the skin, often with a central pore or "punctum"
Texture: Firm or slightly soft to the touch
Size: Ranges from a few millimeters to several centimeters
Color: Flesh-colored or slightly yellow; may appear red if inflamed or infected
Location: Commonly found on scalp, back, face, neck, and chest
Sensation: Usually painless, May become tender, red, or painful if infected or inflamed, andCan drain foul-smelling fluid if ruptured
What Causes It?
Cysts form when a duct or gland becomes blocked, trapping keratin, oil, or other substances beneath the skin. Specific causes vary depending on the type of cyst:
Epidermoid cysts: Caused by buildup of keratin beneath the skin, often due to blocked hair follicles
Sebaceous cysts: Arise from sebaceous glands and are filled with sebum
Pilar cysts: Often found on the scalp and are linked to hair follicles
Other contributing factors:
Skin trauma or irritation
Genetics (especially for pilar cysts)
Acne or oily skin
Previous infections or blockages
Cysts are not contagious and typically not cancerous, though rare types may require further evaluation.
When to See a Doctor?
Most cysts are harmless, but consult a doctor or dermatologist if you notice:
Rapid growth or increasing size
Pain, redness, or warmth (signs of infection)
Foul-smelling drainage
Changes in color or appearance
Recurring cysts in the same location
A cyst that won’t heal or reappears after draining
A medical professional can usually diagnose a cyst through a physical exam; sometimes imaging or a biopsy is done if the diagnosis is uncertain.
Treatment Options
Treatment isn’t always necessary unless the cyst is bothersome, infected, or cosmetically concerning.
Non-Surgical Management
Warm compresses: May help small cysts drain on their own
Antibiotics: If the cyst becomes infected
Steroid injections: To reduce inflammation in inflamed cysts
Surgical Options
Incision and drainage (I&D): Provides temporary relief but cyst may return
Surgical excision: Complete removal of the cyst and sac; helps prevent recurrence
Laser removal or punch excision: Used for smaller or hard-to-reach cysts
Do not try to squeeze or pop cysts at home—this can lead to infection, scarring, or recurrence.
Living With It
Most cysts are harmless and don’t interfere with daily life. However, they can be annoying, painful, or embarrassing depending on their size or location.
Keep the area clean and protected
Avoid picking or squeezing
Monitor for signs of infection
Discuss treatment options if a cyst becomes recurrent or affects your confidence
Whether you choose to leave it alone or have it removed, cysts are treatable and rarely pose a serious health risk. A dermatologist can help determine the best option for you.
If you have further questions about Cysts or would like to schedule an appointment with a dermatologist please give us a call at 865-545-0900 or schedule online via book my appointment. If you have any questions, fill out our appointment request and we’ll reach out to you within a business day.
