A single headache that resolves within a few hours, even up to a day, is rarely a reason to seek medical care. But a headache lasting more than 72 hours, headaches occurring more than 15 days per month, or any headache that reaches peak intensity within seconds all cross into territory that warrants professional attention. The specific threshold depends less on a single number and more on the pattern: how often, how severe, how different from your usual experience.
The 72-Hour Rule for a Single Headache
Most tension headaches last 30 minutes to a few hours. Migraines typically run 4 to 72 hours. If a headache persists beyond three full days without letting up, that duration alone is reason to get evaluated. A headache that lingers past 72 hours may signal that something beyond a standard headache is going on, or that the headache has entered a cycle your body can’t break on its own.
Even within that window, pay attention to how the headache responds to over-the-counter pain relievers. The Mayo Clinic flags headaches that “worsen or don’t improve with appropriate use of over-the-counter drugs” as a reason to see a doctor. If you’ve taken ibuprofen or acetaminophen at normal doses and the pain hasn’t budged after a reasonable period, that’s meaningful information.
Frequency Matters as Much as Duration
A headache doesn’t need to be long-lasting to be a problem. Frequent shorter headaches can be just as disruptive and may point to a treatable underlying pattern. The International Classification of Headache Disorders defines chronic migraine as headache occurring on 15 or more days per month for longer than three months, with at least 8 of those days having migraine features. That’s the formal clinical threshold, but you don’t need to hit it before seeking help.
If your headaches are happening more often than they used to, are more severe than your baseline, or are keeping you from working, sleeping, or doing normal activities, those are all valid reasons to make an appointment. A shift in your personal pattern is the key signal. Someone who never gets headaches and suddenly has them weekly is in a different situation than someone who’s had occasional headaches for years.
Headaches That Need Emergency Care
Some headaches require immediate attention, not a scheduled appointment. The most critical is the thunderclap headache: pain that strikes suddenly and peaks within 60 seconds. This type of headache can indicate bleeding in the brain and should be treated as a medical emergency. If someone describes the worst headache of their life and it came on like a switch being flipped, that’s what this looks like.
Other situations that call for emergency care:
- Headache with fever, stiff neck, or confusion. This combination can indicate meningitis or another serious infection.
- Headache after a head injury. Even if the injury seemed minor, a worsening headache afterward needs evaluation.
- Headache with neurological changes. Sudden vision problems, difficulty speaking, weakness on one side of the body, seizures, or an altered level of consciousness all warrant immediate care.
- Headache with systemic symptoms. Fever, night sweats, or unexplained weight loss alongside new headaches can point to an underlying condition like an infection or autoimmune process.
These red flags exist because about 10% of headaches are “secondary,” meaning they’re caused by something else in the body. Doctors use a mental checklist (known by the acronym SNOOP4) to screen for these. It covers systemic symptoms, neurological deficits, sudden onset, older age of first onset (over 50), and changes in an existing headache pattern. You don’t need to memorize the checklist, but knowing the broad categories helps you recognize when something feels off.
New Headaches After Age 50
If you’re over 50 and develop a new type of headache you haven’t experienced before, that alone is considered a red flag. Most primary headache disorders like migraine start earlier in life. A brand-new headache pattern in middle age or later raises the likelihood that something structural or systemic is involved. The American College of Radiology lists older age of onset as one of the specific criteria that often leads doctors to order brain imaging.
The Medication Overuse Trap
Here’s something many people don’t realize: taking pain relievers too frequently can actually cause more headaches. Most guidelines recommend using symptom-relieving medications no more than 10 to 15 days per month, depending on the type. Beyond that threshold, you risk developing medication overuse headache, where the brain essentially adapts to the pain reliever and produces rebound pain when it wears off.
If you find yourself reaching for ibuprofen, acetaminophen, or other over-the-counter headache treatments more than two or three times a week, that’s a strong sign to see a doctor. Not because the medications are dangerous at those doses, but because the frequency suggests your headaches need a different management strategy, likely a preventive approach rather than treating each episode individually.
What Happens at the Appointment
Knowing what to expect can make it easier to actually book the visit. Your doctor will ask about your headache pattern: when they started, how often they occur, where the pain sits, what makes them better or worse, and whether anything changed recently in your life, health, or medications. Keeping a simple log for a couple of weeks before your appointment, even just noting the date, duration, and severity of each headache, gives your doctor much better information to work with.
Most people will not need imaging. A CT scan or MRI is typically reserved for situations where specific red flags are present: neurological symptoms, sudden onset, a history of cancer or immune suppression, or findings during the physical exam like unequal pupil size or swelling behind the eye. The American College of Radiology has identified five physical findings that strongly predict abnormal imaging results: swelling of the optic nerve, impaired consciousness, asymmetric pupil response, progressive visual or neurological symptoms, and paralysis. Without those signals, imaging rarely changes the diagnosis or treatment plan.
Headaches in Children
Children get headaches more often than many parents expect, and most are harmless. But certain patterns in kids deserve prompt medical attention. A headache that wakes a child from sleep is a red flag, as are headaches accompanied by persistent vomiting, vision changes, or personality changes. Headaches with fever and neck stiffness need urgent evaluation at any age, but especially in children. And as with adults, any headache following a blow to the head should be assessed by a doctor.
Children’s headaches that are becoming more frequent or more severe over weeks also warrant a visit, even if each individual episode seems manageable. Kids aren’t always great at describing their symptoms, so a pattern of increasing school absences, reluctance to play, or rubbing their head repeatedly can be the clues parents notice first.