A headache that never seems to go away usually falls into one of two categories: a primary headache disorder where the headache itself is the condition, or a secondary headache triggered by something else in the body. The most common culprits are chronic tension-type headache, chronic migraine, and medication overuse headache. Less common but important causes include neck problems, pressure changes inside the skull, and blood vessel inflammation. Identifying which type you’re dealing with is the first step toward relief.
How “Constant” Is Defined Clinically
In headache medicine, a headache becomes “chronic” when it occurs on 15 or more days per month for at least 3 consecutive months. That threshold applies to both chronic migraine and chronic tension-type headache. Roughly 2.9 billion people worldwide were affected by headache disorders in 2023, and a meaningful percentage of those experience headaches at this chronic level. If your headaches have crossed that 15-day line, you’re no longer dealing with occasional head pain. Something is sustaining the cycle.
Chronic Tension-Type Headache
This is the most common form of constant headache. The pain is typically on both sides of the head, feels like pressure or tightening (not pulsing), and stays at a mild to moderate intensity. It doesn’t get worse when you walk or climb stairs, and it doesn’t cause vomiting. You might notice mild sensitivity to light or sound, but not both at the same time. The pain can last hours, persist all day, or in some cases feel truly unremitting.
What drives this pattern isn’t fully understood, but it often involves sensitized pain pathways in the nervous system, muscle tension in the head and neck, stress, poor sleep, or some combination. People who start with occasional tension headaches can gradually slide into a chronic pattern over months or years, sometimes without realizing how frequent the episodes have become.
Chronic Migraine
Chronic migraine looks different from tension-type pain. To qualify, at least 8 of those 15+ monthly headache days need to have migraine features: one-sided pain, a pulsating quality, moderate to severe intensity, or pain that worsens with normal physical activity like walking. You’ll also typically experience nausea, vomiting, or sensitivity to both light and sound during those episodes.
Many people with chronic migraine describe a near-constant baseline headache punctuated by more severe migraine attacks. The transformation from occasional migraines to chronic migraine often happens gradually, and several factors can push you over the edge: uncontrolled stress, hormonal changes, poor sleep, obesity, caffeine overuse, and one of the most overlooked triggers of all, taking too much pain medication.
Medication Overuse Headache
This is one of the most common and most fixable causes of constant headaches, yet many people don’t realize it’s happening. When you take pain relievers too frequently, your brain adapts to the medication and begins producing rebound pain as each dose wears off. The result is a self-perpetuating cycle: you take a pill, it helps temporarily, the headache returns, and you take another pill.
The thresholds are lower than most people expect. Using simple over-the-counter painkillers like ibuprofen or acetaminophen on 15 or more days per month can trigger this pattern. For combination painkillers, opioids, or migraine-specific medications like triptans, the threshold drops to just 10 days per month. That means taking a triptan every third day is enough to sustain the cycle. The only way to break it is to reduce or stop the overused medication, which often temporarily worsens headaches before they improve.
New Daily Persistent Headache
This is a distinct and frustrating condition. Unlike chronic migraine or tension-type headache, which build gradually over time, new daily persistent headache (NDPH) starts abruptly in someone who previously had no history of frequent headaches. The pain begins on a specific day, often one the person can pinpoint exactly, and simply never stops. It reaches its peak within 3 days of onset and persists daily for more than 3 months.
In some people, the pain is continuous around the clock. In others, it comes in daily episodes lasting several hours that can mimic migraine attacks. NDPH sometimes follows a viral illness, a stressful life event, or a surgical procedure, but in many cases no clear trigger is found. It’s one of the more treatment-resistant headache types, which makes early evaluation important.
Neck Problems Causing Head Pain
The upper part of your spine has a direct wiring connection to the nerves that supply sensation to your face and head. Sensory fibers from the top three vertebrae in your neck converge with the trigeminal nerve, which is the main pain nerve for the head. When joints, discs, or muscles in the upper neck are irritated or dysfunctional, pain can be referred upward into the head.
This type of headache, called cervicogenic headache, is typically felt on one side and often accompanied by restricted neck movement, pain triggered by certain head positions, or tenderness at the base of the skull. It’s chronic by nature and commonly misdiagnosed as migraine or tension-type headache. People who work at desks, have had whiplash injuries, or carry significant neck stiffness are more prone to it. Physical therapy targeting the upper cervical spine is often the most effective treatment.
Hemicrania Continua
If your constant headache is strictly on one side and never switches sides, hemicrania continua deserves consideration. This is a continuous unilateral headache lasting at least 3 months, with periodic flare-ups of more intense pain. During those flare-ups, you may notice tearing or redness of the eye on the affected side, nasal congestion, drooping of the eyelid, facial sweating, or a feeling of restlessness.
What makes this condition unique is its complete response to a specific anti-inflammatory drug (indomethacin). Pain typically disappears within 2 hours of taking it and returns within 6 to 24 hours of stopping. That dramatic on/off response is actually used as a diagnostic test. If your one-sided constant headache vanishes with indomethacin, you have your answer.
Pressure Changes Inside the Skull
Both too much and too little pressure of the fluid surrounding your brain can produce constant headaches, though they behave very differently.
High Pressure
Idiopathic intracranial hypertension occurs when cerebrospinal fluid builds up excessively inside the skull, putting pressure on the brain and the optic nerve at the back of the eye. It causes persistent headaches along with ringing in the ears, and in some cases, vision changes. It’s more common in younger women and in people who are overweight. Left untreated, it can damage vision permanently, so any headache paired with visual disturbances or pulsing sounds in the ears warrants prompt evaluation.
Low Pressure
Spontaneous intracranial hypotension is caused by a leak of cerebrospinal fluid, usually from a tear in the membrane surrounding the spinal cord. The hallmark is an “orthostatic” headache, meaning the pain gets significantly worse when you stand up and improves when you lie down. This positional pattern is the key clue. With conservative treatment like bed rest and fluids, the headache may resolve over 4 to 24 weeks, and a targeted procedure to seal the leak can bring relief within 16 to 24 hours.
Blood Vessel Inflammation in Older Adults
Giant cell arteritis is an inflammatory condition of the blood vessels that almost exclusively affects people over 50, with peak incidence around age 80. It causes a new, persistent headache often concentrated around the temples, along with scalp tenderness, fatigue, fever, weight loss, and a particularly telling symptom: jaw pain that comes on while chewing and stops when you rest your jaw. This “jaw claudication” occurs in up to 50% of cases and is caused by reduced blood flow to the chewing muscles.
This condition is a medical urgency because it can cause permanent vision loss if the inflammation affects the arteries supplying the eyes. Any new persistent headache in someone over 50, especially with scalp tenderness or jaw pain while eating, needs rapid blood work and evaluation.
Warning Signs That Need Urgent Attention
Most constant headaches, while miserable, aren’t dangerous. But certain features suggest something more serious is going on. Headache specialists use a checklist of red flags to screen for secondary causes that could be life-threatening:
- Sudden, explosive onset: a “thunderclap” headache reaching maximum intensity within seconds to minutes
- Neurological symptoms: weakness, numbness, confusion, difficulty speaking, or decreased consciousness
- Fever with headache: especially with a stiff neck, which may signal infection
- Positional pattern: dramatically worse standing up or lying down
- New headache after age 65: new-onset persistent headache in older adults has a higher chance of being secondary
- Pattern change: a headache that’s fundamentally different from your usual headaches
- Triggered by coughing, sneezing, or exercise: may indicate a structural problem
- History of cancer or immune system problems: increases the likelihood of a secondary cause
- Following head trauma: even mild injuries can trigger persistent headache syndromes
- Progressive worsening over weeks: a headache that steadily escalates without plateauing
Any of these features shifts the priority from managing the headache to identifying what’s causing it. Imaging and further testing become essential.