A cyst on your head can cause headaches, but whether it actually does depends almost entirely on what kind of cyst it is and where exactly it sits. A small, squishy bump on your scalp, the kind you can feel with your fingers, almost never triggers head pain on its own. Intracranial cysts, which form inside the skull and press against brain tissue or block fluid pathways, are a different story. The relationship between cysts and headaches is surprisingly complicated, partly because cysts show up on brain scans so often that sorting out which ones are causing trouble and which are harmless bystanders is one of neurology’s recurring puzzles.
Scalp Cysts Rarely Cause Headaches
The most common lumps people notice on their heads are epidermoid cysts and pilar (trichilemmal) cysts. These sit in or just under the skin, feel like firm or rubbery nodules, and grow slowly over months or years. They are filled with keratin or other skin-cell debris, and they are almost always painless unless they become infected or inflamed. When an epidermoid cyst on the scalp does hurt, the discomfort is localized to the cyst itself, more of a tender spot than a headache.
One documented concern involves damage to nearby nerves during cyst removal rather than from the cyst itself. A case report described a patient who developed occipital neuralgia, a sharp shooting pain along the back of the head, after surgical excision of an epidermoid cyst near the greater occipital nerve. The authors concluded that the cyst had not been compressing the nerve before surgery; instead, the nerve was injured during the procedure.1PubMed Central. Iatrogenic Occipital Neuralgia After Scalp Epidermoid Cyst Excision: A Rare Case Report So if you have a painless lump on your scalp and also get headaches, the lump is probably not the culprit. The exception is if a cyst has grown large enough to press against a superficial nerve, which is rare, or if it has become infected and the surrounding inflammation has spread.
Intracranial Cysts Are a Different Category
Cysts that form inside the skull, within or around the brain itself, operate under completely different rules. These are not lumps you can feel. They are fluid-filled sacs that develop in the membranes surrounding the brain, within the brain’s ventricles, or in specific anatomical niches. Because the skull is a rigid box, anything that takes up space or blocks the normal flow of cerebrospinal fluid can raise pressure inside the head, and increased intracranial pressure is one of the most reliable triggers for headache.
Several types of intracranial cysts are known to cause headaches, each through slightly different mechanisms. The main ones worth understanding are arachnoid cysts, colloid cysts, pineal cysts, and dermoid cysts.
Arachnoid Cysts and the Pressure Question
Arachnoid cysts are the most common type of intracranial cyst. They form between the layers of the arachnoid membrane, one of the coverings of the brain, and are filled with cerebrospinal fluid. Most are congenital, meaning they have been there since birth. Many people carry small arachnoid cysts their entire lives without knowing it.
When arachnoid cysts do cause symptoms, headache is the most frequent complaint. A prospective study that directly measured pressure inside temporal arachnoid cysts found that patients with higher intracystic pressure reported worse headaches before surgery. Both high-pressure and low-pressure groups improved after surgical decompression, but the relationship between pressure and symptoms was not perfectly straightforward. The researchers noted that even patients whose cyst pressure fell within the normal range for intracranial pressure still had symptoms, suggesting that factors beyond raw pressure, such as changes in the brain’s ability to absorb and adjust to pressure shifts, play a role.2Journal of Neurology, Neurosurgery & Psychiatry. Intracystic pressure in patients with temporal arachnoid cysts: a prospective study of preoperative complaints and postoperative outcome
In rare cases, arachnoid cysts overwhelm the brain’s compensatory mechanisms and cause unmistakable signs of elevated intracranial pressure, including severe headache, nausea, and swelling of the optic discs. A pediatric case series described four children whose arachnoid cysts caused exactly this scenario, and all improved after surgical shunting.3PubMed. Symptomatic increased intracranial pressure due to arachnoid cysts One case report even linked an arachnoid cyst to cluster headache, speculating that intermittent rises in pressure might have triggered the pain by disturbing local nerve function near the base of the brain.4PubMed Central. Cluster headache and arachnoid cyst
Colloid Cysts and Positional Headaches
Colloid cysts are small, round, gel-filled growths that almost always appear in the third ventricle of the brain, right where cerebrospinal fluid needs to pass through. They account for a tiny fraction of intracranial tumors, roughly half a percent, but headache is their hallmark symptom.5PubMed. Colloid cyst headache
What makes colloid cyst headaches distinctive is their pattern. They tend to be intermittent, intense, and frontal, often starting suddenly and resolving just as quickly. A widely accepted explanation is that the cyst acts like a ball valve: as you move your head, the cyst shifts position, intermittently blocking the flow of cerebrospinal fluid and causing a sudden spike in pressure. When the cyst rolls out of the way, the blockage clears and the headache eases.6PubMed Central. Colloid Cyst Presenting With Severe Headache and Bilateral Leg Weakness: Case Report and Review This positional quality is a red flag that clinicians watch for. If your headaches dramatically change with head position, especially with sudden onset and resolution, that pattern warrants imaging.
Pineal Cysts and the Aqueduct Bottleneck
Pineal cysts form in the pineal gland, a small structure near the center of the brain. Most are tiny and discovered by accident on MRI scans ordered for unrelated reasons. The vast majority never cause any problems at all.
The scenario where pineal cysts do cause headaches involves their proximity to the cerebral aqueduct, a narrow channel that connects two of the brain’s ventricles. If a pineal cyst grows large enough to press on this channel and narrow it, cerebrospinal fluid backs up. One study found that disabling headaches in patients with pineal cysts were associated with narrowing of the cerebral aqueduct, even in patients who did not have obvious hydrocephalus on imaging.7PubMed. Pineal Cyst-Related Aqueductal Stenosis as Cause of Intractable Headaches in Nonhydrocephalic Patients A separate study that treated patients endoscopically for this exact problem reported resolution of symptoms in about four out of five cases over a follow-up period of roughly a year.8PubMed. Endoscopic management of pineal cyst-associated aqueductal stenosis
Because pineal cysts are common incidental findings and headaches are common in the general population, the challenge is proving that a particular pineal cyst is causing a particular person’s headaches rather than simply coexisting with them. Clinicians typically look for signs of aqueduct compression on imaging before attributing headaches to a pineal cyst.
Dermoid Cysts and Rupture
Intracranial dermoid cysts are a different entity from the epidermoid cysts you can feel on your scalp. They develop inside the skull, often along the midline of the brain, and contain a mix of skin-related tissue including hair follicles, sebaceous material, and sometimes even teeth. They grow very slowly and may go unnoticed for decades.
The main headache risk from intracranial dermoid cysts comes when they rupture. A ruptured dermoid cyst spills its oily, irritating contents into the cerebrospinal fluid and surrounding brain tissue. This can cause an intense inflammatory reaction, leading to chemical meningitis. Headache is one of the most common symptoms of rupture, along with seizures.9PubMed. Headache in Ruptured Intracranial Dermoid Cysts The type of headache depends on where the cyst is located and where the contents spread, so it can mimic other conditions and be tricky to diagnose without imaging.
Skull Bone Cysts
There is a less well-known category that falls between “scalp lump” and “brain cyst”: cysts that form within the bones of the skull itself. Aneurysmal bone cysts are benign but locally aggressive lesions that can expand the bone, thin its walls, and compress adjacent structures. When one of these develops in the skull base, it can press on venous sinuses or nearby brain tissue. One documented case involved an aneurysmal bone cyst in the occipital condyle that compressed the sigmoid sinus and caused headache, dizziness, and visual disturbances, along with small areas of reduced blood flow in the cerebellum.10PubMed Central. Exploring Aneurysmal Bone Cysts of the Skull: Insights from a Review of the Literature and a Case Report Skull bone cysts are uncommon, but they illustrate that cysts do not need to be inside the brain itself to cause neurological symptoms.
The Incidental Finding Problem
Here is where things get genuinely tricky for patients and doctors alike. If you go in for an MRI because of headaches, there is a reasonable chance the scan will find a cyst, but that does not mean the cyst is causing your headaches. Incidental findings are surprisingly common on brain MRIs obtained for headache evaluation.11PubMed. Incidental Findings and Normal Anatomical Variants on MRI of the Brain in Adults for Primary Headaches
A study of children undergoing MRI for migraine or tension-type headache found that roughly 8 to 13 percent had incidental findings, with arachnoid cysts being the most frequent, followed by pituitary adenomas and pineal cysts.12PubMed Central. MRI findings in children with migraine or tension-type headache In most of these cases, the cysts were not causing the headaches. The children had primary headache disorders, migraines or tension-type headaches, and the cysts happened to be there.
This creates an awkward clinical situation. You have headaches. A scan shows a cyst. The natural assumption is that the cyst explains the headaches. But most small, stable cysts found incidentally are not the cause. Clinicians rely on several clues to sort out the relationship: Does the headache pattern match what the cyst type typically produces? Is there imaging evidence of obstruction, pressure effects, or compression? Did the headaches start or change around the time the cyst was discovered or grew? Does the cyst respond to treatment, and if it does, do the headaches resolve?
This is why getting a second opinion from a neurologist or neurosurgeon is often worthwhile when a cyst shows up on a headache workup. The answer to “is this cyst causing my headaches?” is not always obvious from the scan alone.
When Surgery Helps
For intracranial cysts that are genuinely causing symptoms, surgical treatment tends to produce good outcomes. A population-based study of adults who underwent surgical decompression for arachnoid cysts found that about 82 percent were symptom-free or had only minor complaints at follow-up, though 12 percent reported no improvement and 6 percent actually felt worse.13PubMed Central. A population based study of intracranial arachnoid cysts: clinical and neuroimaging outcomes following surgical cyst decompression in adults A prospective study with longer follow-up showed that about 82 percent of patients reported improvement in headaches, with average pain scores roughly halving after surgery and staying low over time.14PubMed. Surgical decompression of arachnoid cysts leads to improved quality of life: a prospective study-long-term follow-up
The type of surgical approach matters, too. A consecutive cohort study found that endoscopic fenestration, a minimally invasive technique where a small opening is made in the cyst wall to allow fluid to drain, produced the highest improvement rate at about 82 percent, while open surgical resection led to symptom relief in roughly 63 percent of patients.15PubMed. Long term clinical and radiological outcomes following surgical treatment of symptomatic cranial arachnoid cyst: A population based consecutive cohort study
Those numbers highlight an important reality: surgery does not guarantee headache relief. When it fails, one common explanation is that the cyst was not actually the headache source despite appearing to be. The patient may have had a primary headache disorder all along, with the cyst as an innocent bystander. This reinforces why careful preoperative assessment matters.
Post-Surgical Headaches and Scar Neuromas
An ironic twist in the cyst-headache story is that surgery to remove or decompress a cyst can itself create a new headache. Postcraniotomy headache is a recognized condition, and one of its causes is scar neuromas, which are clumps of abnormally regenerating nerve tissue that form at the surgical site. When a nerve is cut or damaged during surgery, the nerve endings attempt to regrow. If that regrowth goes awry, the resulting neuroma can become a persistent source of pain.
Research into scar neuromas after craniotomy suggests that these tangles of nerve fibers develop abnormal electrical activity, essentially becoming hypersensitive pain generators. The continuous signals they send can sensitize pain pathways deeper in the brain, potentially worsening a preexisting headache or producing an entirely new one.16Arquivos de Neuro-Psiquiatria. Scar neuromas as triggers for headache after craniotomy: clinical evidence These postcraniotomy headaches sometimes follow a neuropathic pattern, with burning or shooting pain concentrated around the scar, and they can be difficult to treat.17PubMed Central. Chronic Unilateral Headache Related to Scar Neuromas
This does not mean people should avoid necessary surgery for a symptomatic cyst. It means that if new headaches develop after cyst removal, the surgical scar itself is worth investigating as a potential source, rather than assuming the cyst has come back or the surgery failed.
How Imaging Helps Sort Things Out
If you feel a lump on your scalp, a doctor can often diagnose it with a physical exam alone. But when headaches are involved and an intracranial cyst is suspected, imaging becomes essential. MRI is the primary tool for evaluating cysts inside the skull because it gives excellent detail on soft tissue, fluid content, and the relationship between the cyst and surrounding structures. CT scans are sometimes used as a first step or when MRI is not available, and ultrasound can play a role in evaluating scalp lumps, particularly in children.18PubMed. Lumps and bumps on the head in children: use of CT and MR imaging in solving the clinical diagnostic dilemma
What the radiologist and neurologist look for on imaging goes beyond just spotting the cyst. They assess its size, whether it is compressing nearby structures, whether it is blocking cerebrospinal fluid pathways, and whether there are signs of increased intracranial pressure such as enlarged ventricles. A small, stable cyst with no mass effect in a patient with typical migraine features is almost certainly incidental. A large cyst with visible compression and a headache pattern that matches the expected presentation is more concerning.
Serial imaging, repeating the scan after some months, can also be informative. A cyst that is growing changes the clinical calculation. One that has stayed the same size for years is much less likely to be the headache source.
When a Scalp Cyst Deserves Medical Attention
For the many people who find a bump on their head and worry it could be causing their headaches, there are a few situations where a scalp cyst does warrant a visit to a doctor, even though it is probably not causing head pain. You should have it evaluated if it is growing rapidly, if it becomes red, warm, or tender (signs of infection), if it is firm and fixed to deeper tissue rather than movable under the skin, or if you have any neurological symptoms like vision changes, weakness, or personality changes alongside the lump. Those neurological symptoms are not typical of a simple scalp cyst and would raise concern about a deeper process.
For the purely cosmetic, painless, movable bump that has been sitting on your scalp for months or years without changing, the headaches you are experiencing are far more likely to have a separate cause. Tension-type headache and migraine together account for the vast majority of recurring headaches, and both have nothing to do with scalp cysts. Pursuing headache diagnosis and treatment as its own track, rather than fixating on the bump, is usually the more productive path.