Why am I getting big lumps on my head? Common causes explained

September 26, 2025 •

4 min read

Approximately 10% of the population experiences pilar cysts, one of the most common causes of lumps on the head. Finding a lump can be concerning, so it's important to understand the various reasons behind the question, 'Why am I getting big lumps on my head?' to determine the right course of action.

Quick Summary

Large lumps on the head can result from common benign growths like pilar cysts or fatty lipomas, inflammatory issues such as folliculitis, or a hematoma from an injury. While most lumps are harmless, it is crucial to recognize symptoms that might signal a more serious underlying issue and require medical attention.

Key Points

Pilar Cysts: These are very common, benign growths from hair follicles on the scalp, often painless and hereditary.
Lipomas: A soft, fatty, non-cancerous lump that feels rubbery and moves easily under the skin.
Folliculitis: An inflammatory or infectious condition of the hair follicles, appearing as acne-like bumps that can be itchy or sore.
Trauma: A bump from an injury is a hematoma, a collection of blood that usually resolves on its own, but requires medical attention if severe.
When to See a Doctor: Seek professional medical advice for any lump that grows quickly, is painful, or appears after a serious head injury.
Diagnosis: A physical exam is often enough, but imaging or a biopsy may be used to confirm a diagnosis for suspicious lumps.

Understanding the Common Causes of Head Lumps

Discovering a lump on your head can be unsettling, but in many cases, the cause is benign and easily treatable. There are several potential culprits, ranging from simple skin conditions to small, harmless growths under the skin. Knowing the distinct characteristics of each can help you and your doctor determine the best approach.

Benign Growths and Cysts

Pilar Cysts (Trichilemmal Cysts): These are the most common type of cysts found on the scalp. They arise from hair follicles and form a sac filled with keratin, a protein found in hair and skin. Pilar cysts are typically smooth, firm, and slow-growing, often painless unless they become inflamed or infected. They are frequently hereditary and are more common in middle-aged women.
Lipomas: A lipoma is a benign, soft, fatty growth that develops just beneath the skin. When pressed, it feels soft and rubbery and moves easily under the skin. Lipomas grow slowly and are usually painless, but can cause discomfort if they press on a nerve.
Osteomas: A less common cause, an osteoma is a benign bone growth that forms on the skull. These lumps are hard, immovable, and typically painless, discovered incidentally or when they become noticeable.

Inflammatory and Infectious Conditions

Folliculitis: This condition is an inflammation or infection of the hair follicles on the scalp. It often looks like acne, with small, red, pus-filled bumps that can be itchy, sore, or tender. Folliculitis can be caused by bacteria, fungi, or irritated hair follicles due to sweating, tight headwear, or certain hair products.
Scalp Acne: Just like acne on the face, scalp acne occurs when hair follicles become clogged with oil and dead skin cells. The resulting bumps can be tender and inflamed and may include whiteheads or blackheads.
Seborrheic Dermatitis: A chronic inflammatory skin condition, seborrheic dermatitis can cause bumps alongside flaky, scaly patches on the scalp. While the exact cause is not fully understood, factors like yeast proliferation and hormones may be involved.

Traumatic Injuries

Hematoma: A bump appearing after a blow to the head is often a hematoma, a localized collection of blood outside the blood vessels. The resulting swelling can feel like a firm or soft lump and may be accompanied by bruising. Small hematomas typically resolve on their own within a few days, but a severe head injury requires immediate medical attention.

When to See a Doctor

While most head lumps are harmless, certain signs should prompt a visit to a healthcare professional. You should seek medical advice if:

The lump grows rapidly or changes in shape.
It is painful, tender, or warm to the touch.
It bleeds, oozes, or develops into an open sore.
The lump appeared after a head injury and is accompanied by symptoms like confusion, vomiting, dizziness, or loss of consciousness.
You have other systemic symptoms like fever or unexplained weight loss.

Diagnostic Tools

A doctor will typically perform a physical examination and take a medical history to diagnose a head lump. In some cases, further testing may be necessary:

Ultrasound: Uses sound waves to create an image of the mass, helping to distinguish between a cyst and a solid tumor.
MRI or CT Scan: Provides detailed cross-sectional images, often used if a tumor or underlying trauma is suspected.
Biopsy: Involves taking a small tissue sample for laboratory analysis to determine if the lump is benign or cancerous.

Treatment Options for Head Lumps

Treatment depends on the underlying cause. Some benign lumps may not require any treatment, while others can be managed with simple remedies or a medical procedure.

Home and Over-the-Counter Remedies

For mild cases of folliculitis or scalp acne, improved hygiene and over-the-counter products can help.

Warm Compresses: Applying a warm compress can help reduce swelling and encourage drainage of inflamed follicles or cysts.
Antibacterial Shampoos: Medicated shampoos containing ingredients like benzoyl peroxide, salicylic acid, or antifungals can help with acne and folliculitis.
Stress Management: High stress levels can exacerbate skin conditions like dandruff and scalp acne. Practicing relaxation techniques can be beneficial.

Medical Procedures

For persistent, large, or infected lumps, a doctor may recommend a medical procedure.

Cyst Removal: A dermatologist can surgically remove pilar cysts under local anesthesia, ensuring the cyst wall is removed to prevent recurrence.
Drainage: For infected or inflamed cysts, a doctor may drain the fluid and prescribe antibiotics.
Steroid Injections: Can be used to reduce the size and inflammation of certain lumps like lipomas.

Comparison of Common Head Lumps


Feature	Pilar Cyst	Lipoma	Hematoma (Injury)	Folliculitis
Appearance	Smooth, round, firm bump	Soft, rubbery, movable bump	Swollen, bruised area	Red, pus-filled bumps
Sensation	Usually painless; tender if infected	Generally painless	Tender, painful after injury	Itchy, sore, tender
Mobility	Fixed in place	Moves easily under skin	Fixed and firm	Raised from the skin
Speed of Growth	Slow-growing	Slow-growing	Appears suddenly after trauma	Can appear quickly
Treatment	Surgical removal if needed	Surgical removal if needed	Cold compress, time; medical care for severe symptoms	Medicated shampoo, antibiotics

Conclusion

Finding a lump on your head is a common experience, with many causes being benign and manageable. From common pilar cysts to inflammatory conditions like folliculitis, understanding the potential reasons is the first step toward addressing the issue effectively. For any persistent, painful, or rapidly growing lumps, or those following a head injury, seeking a medical evaluation is the safest course of action. Remember, self-diagnosis is no substitute for a doctor's expertise, so consult a professional for an accurate diagnosis and treatment plan to ensure your health and peace of mind. For more information on general health and wellness, visit the official National Institutes of Health website.

Frequently Asked Questions

No, big lumps on the head are most often benign and not a cause for serious concern. Common examples include cysts and fatty tumors. However, a doctor should evaluate any new, growing, painful, or otherwise concerning lump.

It is very rare for a head lump to be cancerous, but not impossible. Most are benign. A doctor can determine if a lump is suspicious based on its characteristics, such as being hard, immovable, or changing in size or shape over time.

Pilar cysts are typically smooth, firm, and fixed to the scalp, while a lipoma is soft, rubbery, and moves under the skin. Folliculitis appears as smaller, red, pimple-like bumps. A doctor's evaluation is the most reliable way to distinguish between them.

The fastest and safest way depends on the type of lump. For inflammatory issues like folliculitis, a medicated shampoo or warm compress may help. For stubborn or large cysts and lipomas, a doctor may need to perform a simple removal procedure.

A sudden large lump is often a hematoma resulting from an injury or trauma. In other cases, a previously unnoticed, slow-growing cyst or lipoma may have recently become inflamed or infected, causing it to swell rapidly.

Stress can indirectly affect your skin health and contribute to inflammatory conditions like scalp acne or dandruff, which can present as bumps. While stress doesn't directly cause growths like cysts or lipomas, it can worsen skin issues.

Pilar cysts are non-cancerous, fluid-filled sacs that develop from hair follicles, usually on the scalp. They are often hereditary and caused by a buildup of the protein keratin. They can run in families, so genetics are a strong contributing factor.