Does Alzheimer’s Disease Cause Headaches?

Alzheimer’s disease is not generally considered a headache-causing condition. Textbooks on the disease list memory loss, confusion, language difficulties, and behavioral changes as hallmark symptoms, with headaches conspicuously absent from the standard list. But the real picture is more tangled than that clean answer suggests. Certain genetic forms of Alzheimer’s do produce headaches, migraine history appears to raise the risk of developing the disease, and newer Alzheimer’s medications can trigger headaches as a side effect. Understanding where headaches fit into the Alzheimer’s landscape matters for patients, families, and clinicians trying to decode symptoms in people whose ability to communicate pain may already be compromised.

Headaches Are Not a Typical Alzheimer’s Symptom

In the most common, late-onset form of Alzheimer’s disease, headaches do not feature as a recognized symptom. The progressive damage to brain tissue mainly affects regions involved in memory, language, and executive function. A large collaborative re-analysis of case-control studies actually found that a history of severe headaches or migraine was associated with a somewhat lower risk of Alzheimer’s, not a higher one.¹ That finding ran counter to what many clinicians expected, and more recent research has complicated it further. But the baseline message holds: if someone with typical late-onset Alzheimer’s starts getting frequent headaches, the headaches are more likely caused by something other than the Alzheimer’s itself.

A nationwide study of dementia patients found that roughly half had at least one pain-related diagnosis documented in their medical records, and headache appeared in about one in eight of those patients.² That rate does not seem dramatically different from the general older adult population, reinforcing the idea that headaches in Alzheimer’s patients usually stem from other causes: tension, medication side effects, dehydration, dental problems, or the many common ailments of aging.

The Exception With Genetic Alzheimer’s

Where the story changes is in rare, inherited forms of Alzheimer’s disease. These early-onset variants, caused by mutations in genes like presenilin-1 (PSEN1) and amyloid precursor protein (APP), can begin producing symptoms in a person’s thirties or forties. And in these families, headaches show up with striking regularity.

A study of a large Colombian kindred carrying a specific PSEN1 mutation found that affected family members reported headaches significantly more often than unaffected relatives, and many complained of headaches both before and during the course of the disease.³ A separate study examining mutation carriers across different familial Alzheimer’s mutations found that about two-thirds of carriers reported significant recurrent headaches, compared to only a quarter of non-carrier family members. Forty percent of carriers met the criteria for migraine specifically.⁴

What makes this especially interesting is that these headaches appeared in people who did not yet have dementia. The mutation carriers with headaches were still cognitively intact, which suggests the headaches were not a downstream consequence of brain damage but possibly an early sign of the biological process already underway. The amyloid protein buildup that defines Alzheimer’s may irritate blood vessels and surrounding tissue long before it destroys enough neurons to cause memory loss. For families known to carry these mutations, recurrent headaches in a younger relative could be one of the earliest hints that the disease process has begun.

Migraine as a Risk Factor for Later Alzheimer’s

Even outside rare genetic forms, the relationship between headaches and Alzheimer’s appears to run in a direction many people do not expect. Rather than Alzheimer’s causing headaches, a history of migraine seems to raise the risk of developing Alzheimer’s later in life.

A large nationwide cohort study found that people with migraine had roughly a 32 percent higher risk of developing Alzheimer’s disease compared to those without migraine, after adjusting for age, sex, and other health conditions. The link was even stronger for people with chronic migraine, who had close to a 48 percent higher risk, compared to about 26 percent higher for those with episodic migraine.⁵ A systematic review and meta-analysis pooling data from multiple cohort studies confirmed this pattern, finding migraine associated with about a 32 percent increase in Alzheimer’s risk and a 26 percent increase in all-cause dementia risk overall.⁶

Why might migraine set the stage for Alzheimer’s? The two conditions share some overlapping biology. Chronic migraine involves sustained neuroinflammation, changes in blood flow regulation, and disruptions to the blood-brain barrier. These same processes are implicated in the development and progression of Alzheimer’s pathology. Researchers have proposed that years of chronic migraine may make the brain more vulnerable to the protein accumulation and neuronal damage that characterize Alzheimer’s.⁷ This does not mean every person with migraines will develop Alzheimer’s. The absolute risk remains modest, and many other factors are at play. But it does suggest that decades of recurring headaches leave traces on the brain that matter.

Why People With Alzheimer’s May Not Report Headaches

One of the biggest confounders in studying headaches in Alzheimer’s patients is that as the disease progresses, people become less and less able to describe what they are feeling. A person with moderate to advanced Alzheimer’s may not have the language skills to say “I have a headache,” and caregivers may not recognize the signs. Chronic pain in elderly people with cognitive impairment is frequently under-reported and therefore under-treated.⁸

This creates a real clinical problem. Agitation, grimacing, withdrawal, and changes in appetite can all be signs of pain in someone who can no longer verbalize it, but these same behaviors also overlap with the behavioral symptoms of Alzheimer’s itself. A caregiver might attribute a person’s restlessness to the disease when it is actually caused by an untreated headache, toothache, or joint pain. Clinicians working with Alzheimer’s patients increasingly rely on behavioral pain scales rather than self-report, but these tools remain imperfect.

How Alzheimer’s Changes Pain Processing

There is a persistent assumption that Alzheimer’s disease blunts pain perception, which would presumably mean fewer headaches bother these patients. The evidence on this is more nuanced than the assumption suggests.

One study compared pain responses in Alzheimer’s patients to age-matched controls and found no difference in the ability to detect a painful stimulus or in the threshold at which something starts to hurt. Where Alzheimer’s patients did differ was in pain tolerance: they could endure more intense stimulation before asking for it to stop, and this tolerance increased in step with the severity of cognitive decline.⁹ This suggests the issue is not that the brain stops registering pain. Instead, the higher-order processing of pain (the part that decides how much distress a painful signal should cause and what to do about it) seems to be what changes.

A brain imaging study added a provocative wrinkle. When researchers delivered mechanical pressure to Alzheimer’s patients and healthy controls while scanning their brains, they found that pain-related brain activity was not diminished in the Alzheimer’s group. It was actually more intense and more prolonged, particularly in regions linked to attention and emotional processing.¹⁰ The researchers interpreted this as evidence that Alzheimer’s patients may pay sustained attention to a painful stimulus because their brains struggle to disengage from it, even though they may report less distress verbally. This finding challenges the idea that Alzheimer’s patients simply feel less pain and raises concerns that their pain is being inadequately treated.

These findings have direct implications for headaches. If a person with Alzheimer’s experiences a headache, their brain may register it fully, perhaps even amplify it, while their ability to communicate or respond to it diminishes. The neuronal damage in Alzheimer’s affects neurotransmitter systems involved in both cognition and pain modulation, creating a complex interplay where pain signals persist but the behavioral response to them becomes muted or distorted.¹¹

Cerebral Amyloid Angiopathy and Headache Mimics

Alzheimer’s disease frequently coexists with a condition called cerebral amyloid angiopathy, or CAA, in which amyloid protein deposits build up in the walls of blood vessels in the brain. CAA can produce episodes that look remarkably like migraine aura: brief, recurring attacks of tingling, numbness, visual disturbances, or weakness that spread gradually across one side of the body. These transient focal neurological episodes are often initially misdiagnosed as strokes (TIAs), seizures, or migraine with aura.¹²

The distinction matters enormously. CAA-related episodes carry a meaningful risk of brain hemorrhage, particularly when accompanied by certain imaging findings. When these episodes are mistaken for ordinary migraine or TIA and treated with blood-thinning medications, the risk of bleeding increases. In one case series, several patients who were prescribed standard anti-clot therapy went on to develop intracranial hemorrhages. For someone with Alzheimer’s who starts having migraine-like episodes, the possibility of CAA should be investigated rather than dismissed as “just headaches.” Brain MRI sequences that detect tiny bleeds and iron deposits on the brain surface can help clinicians make the right call.

Headaches From Alzheimer’s Medications

One increasingly common source of headaches in Alzheimer’s patients is the medications used to treat the disease. A new class of drugs called anti-amyloid antibodies, including lecanemab and donanemab, has generated both hope and concern. These drugs work by clearing amyloid plaques from the brain, but they carry a risk of a side effect called amyloid-related imaging abnormalities, or ARIA, which involves swelling or tiny bleeds in the brain. While most cases of ARIA show up only on brain scans without causing symptoms, symptomatic cases can produce headache, confusion, dizziness, and nausea.¹³

An analysis of adverse events reported to the FDA for lecanemab found that headache was the single most frequently reported side effect, more common than chills, fatigue, or even the ARIA-related brain swelling itself. The headache signal was strong: reporting rates were roughly ten times what would be expected compared to other drugs in the FDA’s database.¹⁴ A comparative safety analysis of both lecanemab and donanemab found the same pattern: headache and infusion-related reactions were among the most commonly reported events for both drugs.¹⁵

For patients and caregivers, this creates a practical dilemma. A person starting one of these new treatments who develops headaches needs monitoring. Most headaches are likely benign infusion reactions that resolve on their own, but some could signal ARIA, which requires medical imaging and potentially pausing treatment. Clinicians typically schedule regular brain MRI scans during the first months of therapy to catch ARIA early, regardless of whether the patient reports symptoms. Given the communication challenges in Alzheimer’s patients, caregivers should watch for behavioral cues such as agitation, holding the head, or withdrawal, which could indicate headache even when the person cannot articulate it.

Other Medical Causes Worth Ruling Out

When an Alzheimer’s patient does develop headaches, the list of possible causes extends well beyond the disease itself. Older adults are more prone to conditions like chronic subdural hematomas, which are collections of blood that slowly accumulate between the brain and its outer covering, often after a minor head bump that the person may not even remember. Cognitive impairment and headache are two of the most common symptoms of this condition. Falls are common in Alzheimer’s patients, and a subdural hematoma can develop weeks after a head injury that no one witnessed.

Medication side effects beyond the anti-amyloid drugs are another frequent culprit. Many Alzheimer’s patients take medications for coexisting conditions like high blood pressure, depression, or pain, and headache is a common side effect across dozens of drug classes. Dehydration is also a significant factor, since people with Alzheimer’s often forget to drink enough fluids, and even mild dehydration can trigger headaches. Eye strain from vision changes, poorly fitting dentures causing tension-type headaches, and sinus infections that the person cannot describe all belong on the checklist.

The key takeaway for caregivers is not to assume that new headaches are either “part of Alzheimer’s” or “nothing to worry about.” Neither assumption is reliably correct. Any new or worsening headache pattern in someone with Alzheimer’s warrants a medical evaluation, especially given how many treatable causes exist and how poor the person’s ability to describe their own symptoms may be.

The Paradox of Historical Headache and Future Dementia Risk

Researchers are still sorting out what looks like a paradox in the data. Earlier case-control studies suggested people with a headache history might have a lower risk of Alzheimer’s, while more recent large cohort studies and meta-analyses point in the opposite direction, showing migraine as a risk factor. The discrepancy likely comes down to study design. Case-control studies, which ask patients or families to recall medical history after diagnosis, are vulnerable to recall bias. A person already struggling with memory is less likely to accurately report a lifetime of headaches. Their family members may also undercount past headaches that were never discussed. Prospective cohort studies, which follow large populations forward in time and track diagnoses as they happen, avoid this problem and have consistently found that migraine elevates dementia risk.

This matters because it reshapes how clinicians think about mid-life migraine. Rather than viewing migraine purely as a pain condition to manage in the moment, there is growing interest in whether effective migraine treatment over decades could have downstream effects on brain health. The shared biology between chronic migraine and Alzheimer’s involves inflammation, blood-brain barrier integrity, and vascular function. Whether reducing migraine burden actually protects against Alzheimer’s remains unproven, but the epidemiological link has prompted researchers to look more carefully at whether certain migraine treatments have neuroprotective effects or, conversely, whether some could worsen long-term cognitive outcomes.

For anyone who has lived with migraine for years and worries about Alzheimer’s risk, the increased hazard ratio, while statistically real, needs to be kept in perspective. Moving from a baseline risk to a roughly 30 percent higher risk sounds alarming in percentage terms but represents a modest absolute increase for most people. The standard advice for reducing dementia risk still applies: manage cardiovascular health, stay physically and socially active, treat hearing loss, limit alcohol, and control conditions like diabetes and hypertension that damage blood vessels over time. Treating migraine effectively belongs on that list not because the evidence proves causation, but because the biological overlap is plausible enough to take seriously.