A painful, localized lump on the head or scalp that hurts when touched can be an alarming symptom. The symptom itself is remarkably common and typically points to a benign, easily treatable cause. Understanding why these bumps form and become tender involves looking at the structures beneath the skin, including fat, hair follicles, lymph nodes, and even the muscles of the head and neck. The source of the pain on pressure is often not the lump itself, but the resulting inflammation that irritates nearby nerve endings in the highly sensitive scalp tissue. While most cases are harmless, the presence of a new lump always warrants investigation. Determining the exact cause relies on examining the texture, mobility, location, and accompanying symptoms of the bump.
Benign Skin and Soft Tissue Lumps
A frequent cause of a painful lump on the head is a simple, non-cancerous growth originating in the skin or the layers directly beneath it. These masses are generally slow-growing and only cause pain when they become inflamed or when pressure is applied to their encapsulated walls. The two most common types are cysts and lipomas, which have distinct characteristics. Epidermoid cysts, often incorrectly called sebaceous cysts, are the most prevalent type of skin cyst, forming when surface skin cells are trapped beneath the skin instead of shedding. These cells multiply and secrete keratin, a thick, cheese-like protein that fills the sac. An epidermoid cyst is typically smooth and movable beneath the skin, but it becomes acutely painful if the sac ruptures, spilling the keratin contents into the surrounding tissue and triggering a massive inflammatory response.
Lipomas are another common benign lump, consisting entirely of fatty tissue cells enclosed in a fibrous capsule. These growths feel soft, doughy, and are easily moved with a finger press, distinguishing them from firmer lesions. While typically painless, a lipoma can cause tenderness if it grows large enough to compress a sensory nerve in the scalp. A less common variant, the angiolipoma, contains small blood vessels in addition to fat, which makes it inherently more sensitive and painful to the touch even without significant size. The pain from these soft tissue lumps is almost always proportional to the degree of inflammation or infection present. A rapidly swelling, infected cyst will be exquisitely painful because of the pressure building up inside the tight, non-stretchy scalp skin.
Causes Related to Localized Inflammation and Infection
Lumps that appear acutely painful and are accompanied by redness and warmth often result from an active immune response to an infection or localized irritation. The acute nature of the pain helps distinguish these from the more chronic tenderness of uninfected cysts. Folliculitis, a bacterial or fungal infection of a hair follicle, can create small, red, pimple-like bumps that are tender to the touch. When this infection progresses deeper, it forms a larger skin abscess, known as a boil or furuncle, which is a collection of pus and necrotic tissue. The intense pain experienced when pressing on an abscess is caused by the substantial internal pressure exerted by the accumulation of pus against the rigid surrounding tissue.
Another common source of tenderness is the swelling of lymph nodes, specifically the occipital nodes at the base of the skull or the post-auricular nodes behind the ear. These nodes are part of the lymphatic system, acting as filters that trap pathogens draining from the scalp. They become swollen, firm, and tender when they are actively fighting an infection like a minor scalp cut, severe dandruff, or a fungal infection. Localized allergic reactions, such as those from an insect bite or sting, can also create a tender lump that mimics a more permanent mass. The body’s immediate release of inflammatory mediators causes rapid swelling and tenderness around the bite site.
Tenderness from Muscular Tension and Deeper Structures
Not every painful spot that feels like a bump is a true mass; sometimes, the sensation is caused by underlying structural or neurological irritation. The muscles and nerves that cover the skull can be subject to tension that creates highly sensitive points often misidentified as a lump. These conditions are typically characterized by a deeper, more diffuse ache than a skin lesion. Myofascial trigger points, commonly referred to as muscle knots, are hyperirritable spots in the taut bands of muscle, particularly in the occipitalis muscle that covers the back of the head. When palpated, these knots can be distinctly felt as small, hard nodules that are acutely painful and may even refer pain to other areas of the scalp. This localized muscle spasm is often a result of chronic stress or poor posture that strains the muscles supporting the head and neck.
Irritation or inflammation of the occipital nerves, known as occipital neuralgia, can cause intense, shooting pain that radiates across the back of the head and scalp. This neurological irritation can lead to allodynia, where even a light touch causes severe pain and the general area feels profoundly tender. A less frequent but intensely tender cause is localized irritation of the periosteum, the thin, highly innervated membrane covering the skull bone. Minor trauma can inflame this membrane without causing a visible hematoma. Periosteal irritation results in extreme, bony tenderness when pressed, often feeling like a fixed, hard lump.
Warning Signs and When to Consult a Doctor
While most painful head lumps are benign, it is important to recognize specific signs that indicate the need for prompt medical evaluation. A doctor’s assessment is the only reliable way to rule out rare but serious conditions. Self-care is appropriate only for known, minor causes, such as a recent insect bite or a small, resolving pimple. Immediate medical attention is necessary if the lump is accompanied by severe, rapidly worsening symptoms, particularly those that suggest a neurological issue.
Red flags include:
- A severe headache that does not improve.
- Persistent vomiting.
- Confusion or slurred speech.
- Changes in vision or balance.
These symptoms may indicate complications such as a post-traumatic hematoma or internal pressure. A consultation is also warranted if the lump is growing rapidly over a few weeks, feels hard and immobile (fixed to the underlying bone or deep tissue), or is accompanied by systemic signs of infection such as fever and chills. Any lump that persists for more than two weeks, even if only mildly tender, should be professionally evaluated. A medical professional will perform a physical examination to assess the lump’s texture, size, and mobility. They may order diagnostic imaging, such as an ultrasound, CT scan, or MRI, to visualize the deep tissues or bone. If the nature of the lump remains unclear, a skin biopsy may be performed for definitive diagnosis.