14 Types of Cysts: Causes, Symptoms, and Warning Signs You Shouldn’t Ignore

Cysts are abnormal, fluid-filled sacs that can develop almost anywhere in the body. While many cysts are benign and cause no symptoms, others can signal underlying health issues that require medical attention. Understanding the different types of cysts, their causes, and warning signs can help you determine when to seek professional care.

A cyst is a closed pocket or pouch of tissue that contains fluid, air, or other substances. Unlike tumors, which are solid masses of tissue, cysts are typically filled with a liquid or semi-solid material. They can vary greatly in size, from microscopic to several centimeters in diameter.

Cysts form through various mechanisms depending on their location and type. Some develop due to blocked ducts or glands, while others result from infections, genetic conditions, or cellular defects. While many cysts are harmless, certain characteristics or symptoms may indicate a more serious condition.

Medical professionals typically diagnose cysts through physical examinations, imaging studies (such as ultrasounds, CT scans, or MRIs), and sometimes through tissue sampling. Treatment approaches range from watchful waiting to drainage procedures or surgical removal, depending on the cyst’s type, location, and associated symptoms.

1. Epidermoid Cysts

Causes and Formation

Epidermoid cysts, sometimes incorrectly called sebaceous cysts, develop when surface skin cells move deeper into the skin rather than shedding naturally. These misplaced cells multiply and form the wall of the cyst, gradually producing a protein called keratin that fills the growing sac.

The most common causes include:

• Blocked hair follicles due to skin oils, debris, or injury
• Skin trauma that pushes surface cells deeper into the skin
• Genetic conditions such as Gardner’s syndrome that predispose to cyst formation

Common Locations and Symptoms

Epidermoid cysts most frequently appear on the face, neck, back, and genitals. They present as small, round bumps under the skin with the following characteristics:

• Slow-growing, painless lumps that move freely under the skin
• A visible central blackhead or pore
• A thick, yellow, cheese-like discharge if ruptured
• Occasional foul odor due to keratin content

Warning Signs

Seek medical attention if your epidermoid cyst:

• Becomes painful, inflamed, or red
• Ruptures, which can lead to inflammation and infection
• Grows rapidly or exceeds 5 cm in diameter
• Recurs after previous removal
• Develops in a sensitive or problematic location

2. Sebaceous Cysts

Formation and Characteristics

True sebaceous cysts form from blocked sebaceous glands, which normally produce sebum, the oil that lubricates hair and skin. When these glands become obstructed, sebum accumulates within the gland, causing it to expand and form a cyst.

Sebaceous cysts commonly develop on the scalp, face, ears, and back, where sebaceous glands are most abundant. They share many characteristics with epidermoid cysts but contain oily sebum rather than keratin.

Symptoms and Appearance

• Round, dome-shaped lumps beneath the skin
• Smooth texture with a yellowish or whitish appearance
• Generally painless unless infected
• Oily or cheese-like contents when expressed

When to Seek Treatment

Medical evaluation is recommended when sebaceous cysts:

• Show signs of infection (redness, warmth, tenderness)
• Interfere with daily activities due to location or size
• Cause cosmetic concerns
• Rupture or drain spontaneously

3. Ganglion Cysts

Formation and Affected Areas

Ganglion cysts are fluid-filled lumps that form along the tendons or joints of wrists, hands, ankles, and feet. They develop when synovial fluid, which lubricates the joints and tendons, leaks and collects in a sac formed by surrounding tissue.

The exact cause remains unclear, but these cysts often develop following:

• Joint or tendon irritation
• Mechanical changes in the joint
• Traumatic injury
• Repetitive stress or microtrauma

Symptoms and Appearance

Ganglion cysts typically appear as:

• Round or oval lumps, from pea-sized to 2.5 cm in diameter
• Firm or spongy masses that feel smooth under the skin
• Translucent structures that may transmit light
• Painless swellings, although they may cause aching, discomfort, or weakness if pressing on nerves

Warning Signs of Complications

Consult a healthcare provider if you experience:

• Pain or increased discomfort associated with the cyst
• Interference with joint mobility or daily activities
• Cysts that change in size or appearance rapidly
• Numbness or tingling in the affected limb

4. Pilonidal Cysts

Causes and Risk Factors

Pilonidal cysts form near the tailbone (coccyx) at the top of the cleft between the buttocks. They develop when hair penetrates the skin and becomes embedded, creating a foreign body reaction and subsequent cyst formation.

Risk factors include:

• Male gender (more common in men)
• Age between 20-40 years
• Coarse or stiff body hair
• Prolonged sitting or sedentary lifestyle
• Obesity
• Family history of pilonidal cysts
• Local trauma or friction in the sacrococcygeal area

Symptoms and Discomfort

Pilonidal cysts typically present with:

• Pain, tenderness, or swelling above the tailbone
• Small dimple or pit in the skin
• Drainage of pus or blood from the opening
• Foul odor from the discharge
• Difficulty sitting or discomfort with movement

Infection Signs Requiring Attention

Seek immediate medical care if you notice:

• Severe, throbbing pain in the cyst area
• Noticeable redness, warmth, and swelling
• Fever or chills
• Purulent discharge (pus) from the cyst
• Multiple sinus tracts or openings in the skin

5. Ovarian Cysts

Types and Causes

Ovarian cysts are fluid-filled sacs that develop on or within the ovaries. They are classified into two main categories:

Functional Cysts

• Follicular cysts: Form when the follicle doesn’t rupture to release an egg during ovulation
• Corpus luteum cysts: Develop when the corpus luteum (the follicle after ovulation) doesn’t dissolve properly

Pathological Cysts

• Dermoid cysts: Contain tissue such as hair, skin, or teeth
• Cystadenomas: Develop from ovarian tissue and can contain watery or mucous material
• Endometriomas: Form when endometrial tissue grows on the ovaries

Hormonal imbalances, endometriosis, pelvic infections, and genetic predispositions can all contribute to ovarian cyst formation.

Symptoms Women Should Monitor

Many ovarian cysts cause no symptoms and resolve on their own. However, women should be alert to:

• Pelvic pain or pressure, often dull and aching
• Bloating or abdominal swelling
• Pain during intercourse
• Changes in menstrual patterns
• Frequent urination due to pressure on the bladder
• Difficulty emptying the bowels

Red Flags Indicating Emergency

Seek immediate medical attention for these symptoms, which may indicate a ruptured cyst or ovarian torsion:

• Sudden, severe abdominal or pelvic pain
• Pain accompanied by fever or vomiting
• Symptoms of shock, such as cold, clammy skin or rapid breathing
• Dizziness or weakness
• Heavy vaginal bleeding

6. Baker’s Cysts

Formation Behind the Knee

A Baker’s cyst, also called a popliteal cyst, forms when synovial fluid accumulates in the space behind the knee. The buildup occurs when excess knee joint fluid is pushed into the popliteal bursa (a small sac filled with fluid) and forms a bulge.

Connection to Joint Problems

Baker’s cysts typically develop due to underlying knee joint issues, including:

• Osteoarthritis
• Rheumatoid arthritis
• Meniscus tears
• Cartilage damage
• Gout
• Infections of the joint

Symptoms and Limitations

Common symptoms include:

• Swelling behind the knee, often more noticeable when standing
• Knee pain that worsens with activity or bending
• Stiffness or tightness in the knee
• Sensation of fullness or pressure behind the knee
• Limited range of motion

Warning Signs of Rupture

A ruptured Baker’s cyst requires medical evaluation and presents with:

• Sudden calf pain, often resembling a blood clot
• Swelling, redness, or warmth in the calf
• A sensation of water running down the leg
• Bruising of the knee and calf

7. Breast Cysts

Types and Formation

Breast cysts are fluid-filled sacs within breast tissue and are among the most common benign breast conditions. They typically develop when fluid accumulates within the breast glands.

Types of breast cysts include:

• Microcysts: Too small to feel but visible on ultrasound
• Macrocysts: Large enough to be felt and sometimes painful
• Simple cysts: Contain only fluid with thin walls
• Complex cysts: Contain both fluid and solid components

Hormonal Influences

Breast cysts are strongly influenced by hormonal factors, including:

• Fluctuations during the menstrual cycle
• Hormone replacement therapy
• Perimenopause and hormonal changes

They most commonly affect women between 35-50 years of age and often resolve after menopause.

Symptoms and Self-Examination

Breast cysts may present as:

• Round or oval lumps with distinct edges
• Smooth, easily movable masses under the skin
• Tenderness or pain, especially before menstruation
• Increase and decrease in size with hormonal fluctuations
• Clear, yellow, or brown fluid if aspirated

When to Consult a Doctor

Seek medical evaluation for:

• Any new breast lump or change in breast tissue
• Persistent or severe breast pain
• Changes in the skin over the breast, such as dimpling or redness
• Nipple discharge, especially if bloody or clear
• Complex cysts found on imaging studies

8. Bartholin’s Cysts

Formation in Female Reproductive System

Bartholin’s glands are located on either side of the vaginal opening and produce fluid that lubricates the vagina. When the ducts of these glands become obstructed, fluid accumulates and forms a cyst.

Causes and Risk Factors

The most common causes include:

• Bacterial infections
• Sexually transmitted infections
• Injury or trauma to the vaginal area
• Thickened mucus blocking the ducts

Risk factors include:

• Sexual activity
• Multiple sexual partners
• Age (most common in women of reproductive age)
• Previous history of Bartholin’s cysts

Symptoms and Discomfort

Bartholin’s cysts often present with:

• Painless swelling near the vaginal opening
• A lump that’s soft and generally not tender
• Discomfort when walking, sitting, or during intercourse
• Pain that develops if the cyst becomes infected (forming an abscess)

Signs of Infection Requiring Treatment

Medical attention is needed if:

• The cyst becomes painful, red, or swollen
• You develop fever or chills
• The area feels hot to the touch
• You experience pain during walking or sexual activities
• The cyst ruptures or drains pus

9. Chalazion and Stye

Formation in Eyelids

Chalazia and styes are both common eyelid cysts but differ in their formation:

• Chalazion: Forms when an oil gland (meibomian gland) in the eyelid becomes blocked and swollen
• Stye (Hordeolum): Develops from an infected eyelash follicle or sweat gland (external stye) or meibomian gland (internal stye)

Differences Between the Two

Symptoms and Appearance

Common symptoms include:

• Localized swelling on the eyelid
• Redness and inflammation
• Tearing or watery eyes
• Sensitivity to light
• Foreign body sensation
• Blurred vision if the cyst is large enough to press on the eye

Warning Signs of Spreading Infection

Seek medical attention if:

• The entire eyelid or area around the eye becomes swollen
• Redness spreads beyond the eyelid to surrounding skin
• Your vision becomes affected
• You experience severe pain
• The cyst doesn’t improve after a few days of home treatment
• You develop fever or chills

10. Renal Cysts

Types of Kidney Cysts

Renal cysts are fluid-filled sacs that form in the kidneys and include:

• Simple cysts: Individual, thin-walled cysts that contain clear fluid
• Complex cysts: Cysts with irregular features that may require further evaluation
• Polycystic kidney disease (PKD): A genetic disorder causing numerous cysts in both kidneys
• Acquired cystic kidney disease: Multiple cysts developing in damaged kidneys

Causes and Risk Factors

Kidney cysts can develop due to:

• Age (more common in people over 50)
• Genetic conditions
• Long-term dialysis
• Tubular blockages
• Previous kidney damage

Symptoms (or Lack Thereof)

Most simple kidney cysts don’t cause symptoms and are discovered incidentally during imaging for other conditions. However, large or multiple cysts may cause:

• Dull pain or discomfort in the upper abdomen or back
• Feeling of fullness in the abdomen
• High blood pressure
• Blood in urine (if the cyst ruptures)
• Frequent urination

Signs Indicating Polycystic Kidney Disease

Indicators of PKD include:

• Multiple kidney cysts on both kidneys
• Family history of PKD
• Hypertension at a young age
• Declining kidney function
• Cysts in other organs like the liver
• Urinary tract infections
• Kidney stones

11. Thyroid Cysts

Formation Within Thyroid Nodules

Thyroid cysts develop within the thyroid gland, located at the base of the neck. They form when thyroid nodules fill with fluid, creating sac-like structures. These cysts can be:

• Pure cysts: Containing only fluid
• Mixed or complex cysts: Containing both fluid and solid components

Potential Causes

The exact cause of thyroid cysts is often unknown, but they may be associated with:

• Overgrowth of normal thyroid tissue
• Degenerating thyroid adenomas (benign tumors)
• Iodine deficiency or excess
• Thyroiditis (inflammation of the thyroid)
• Genetic factors

Symptoms to Monitor

While many thyroid cysts are asymptomatic, possible signs include:

• Visible swelling at the base of the neck
• Sensation of fullness or pressure in the neck
• Difficulty swallowing (dysphagia)
• Voice changes or hoarseness
• Discomfort when wearing tight collars

Warning Signs Requiring Evaluation

Medical attention is recommended if:

• The cyst grows rapidly
• You experience trouble breathing or swallowing
• Your voice becomes persistently hoarse
• You develop pain in the neck or ear
• You notice enlarged lymph nodes
• You experience symptoms of hyper- or hypothyroidism (weight changes, heart palpitations, fatigue, hair loss)

12. Pineal Cysts

Formation in the Pineal Gland

Pineal cysts develop within the pineal gland, a small endocrine gland located in the brain that produces melatonin. These fluid-filled sacs form when the pineal gland’s normal structure develops small cavities that fill with fluid.

Typical Size and Characteristics

Pineal cysts typically:

• Measure between 5-15 mm in diameter
• Contain clear, colorless fluid
• Have smooth, thin walls
• Appear round or oval on imaging
• Do not enhance significantly with contrast during MRI

Common Symptoms (If Any)

Most pineal cysts are asymptomatic and discovered incidentally during brain imaging for unrelated conditions. However, some people may experience:

• Headaches, particularly when changing position
• Visual disturbances
• Nausea or vomiting
• Dizziness or vertigo
• Sleep disturbances

Warning Signs of Pressure on Brain

Seek immediate medical attention for these symptoms, which may indicate the cyst is causing intracranial pressure:

• Sudden, severe headache
• Visual changes, including double vision
• Difficulty with eye movements
• Balance problems or coordination issues
• Hydrocephalus symptoms (increased head circumference in children, cognitive changes)
• Seizures

13. Synovial Cysts

Formation Near Spinal Facet Joints

Synovial cysts develop as outpouchings of the synovial membrane that lines facet joints in the spine. These joints connect the vertebrae and allow for movement. When the joint produces excess fluid, it can form a cyst that extends from the joint capsule.

Connection to Degenerative Changes

Spinal synovial cysts are strongly associated with:

• Degenerative spine conditions
• Osteoarthritis of the facet joints
• Spinal instability
• Natural aging processes
• Previous spine trauma or surgery

Symptoms of Nerve Compression

When synovial cysts grow large enough to compress spinal nerves, symptoms may include:

• Localized back pain
• Radiating pain down the legs (if in the lumbar spine)
• Numbness or tingling in the extremities
• Muscle weakness
• Difficulty walking
• Neurogenic claudication (pain while walking that improves with rest)

Warning Signs Requiring Medical Attention

Seek prompt medical evaluation if:

• You experience progressive neurological symptoms (weakness, numbness)
• You develop bowel or bladder dysfunction
• Pain becomes severe or unmanageable
• You notice foot drop or difficulty lifting your foot
• Symptoms significantly impact your daily activities

14. Ganglion Cysts of the Wrist and Hand

Specific Causes in This Location

While we discussed ganglion cysts earlier, those affecting the wrist and hand deserve special attention due to their frequency. These cysts form when joint capsule or tendon sheath weaknesses allow synovial fluid to escape and collect in a sac.

Specific triggers in the wrist and hand include:

• Repetitive wrist movements
• Occupational stress (typing, construction work)
• Previous wrist injuries or sprains
• Degenerative joint disease
• Rheumatoid arthritis

Physical Appearance and Feel

Hand and wrist ganglion cysts typically present as:

• Firm, smooth lumps
• Round or oval-shaped masses
• Variable in size (from pea-sized to 2.5 cm)
• Sometimes fluctuating in size with activity level
• Most commonly located on the back of the wrist (dorsal ganglion)
• Sometimes at the base of fingers or on the palm side of the wrist (volar ganglion)

Impact on Hand Function

Functional impacts may include:

• Weakness in grip strength
• Discomfort when bearing weight on the affected hand
• Limited range of motion
• Pain during specific movements
• Aesthetic concerns

When Surgical Intervention is Needed

Consider medical treatment when:

• The cyst causes persistent pain
• Hand function is significantly impaired
• The cyst is growing or changing rapidly
• Conservative treatments fail to provide relief
• The cyst recurs after aspiration
• Nerve compression symptoms develop

General Warning Signs for All Cysts

Regardless of the type or location of a cyst, certain warning signs should prompt medical evaluation:

Rapid Growth or Change in Size

Any cyst that suddenly enlarges or changes shape warrants professional attention. Rapid growth may indicate infection, inflammation, or rarely, malignant transformation.

Severe Pain or Tenderness

While many cysts are painless, the development of significant pain can signal complications such as infection, rupture, bleeding within the cyst, or pressure on surrounding structures.

Signs of Infection

Watch for classic signs of infection, including:

• Redness and warmth around the cyst
• Increased tenderness or pain
• Discharge of pus
• Fever or chills
• Swollen lymph nodes near the affected area

Cysts That Interfere With Daily Activities

Seek evaluation when a cyst:

• Restricts movement or joint function
• Causes neurological symptoms like numbness or weakness
• Interferes with organ function
• Creates cosmetic concerns that affect quality of life
• Impacts your daily activities or sleep

Conclusion

Cysts are common occurrences in the human body, and while many are harmless and require no treatment, others can signal more significant health concerns. Understanding the different types of cysts, their causes, and most importantly, their warning signs can help you make informed decisions about seeking medical care.

Key points to remember include:

• Most cysts are benign, but certain characteristics warrant professional evaluation
• Any cyst that is painful, rapidly growing, or shows signs of infection requires medical attention
• Different cyst types have specific warning signs related to their location and impact on surrounding structures
• Treatment approaches range from watchful waiting to drainage or surgical removal
• Regular self-examinations and awareness of changes in your body can help detect problematic cysts early

Always consult with healthcare professionals for proper diagnosis and treatment recommendations for any concerning cysts. While this guide provides general information, individual cases may vary, and personalized medical advice is essential for optimal care.