Download AppThis is an educational overview rather than medical advice. If you have warning signs, seek prompt medical care.
Most headaches are primary, meaning conditions like migraine or tension-type headache, and they are not dangerous. A clinician's real job is to catch the small minority that are secondary, caused by something else going on, from infection to raised pressure inside the skull to bleeding. The standard tool for doing that is a checklist called SNNOOP10 (Do et al., Neurology 2019). None of these signs proves something is wrong on its own, but each one lowers the threshold for looking more closely.
The SNNOOP10 warning signs
Each letter points to a feature that should prompt a closer look.
- Systemic symptoms such as fever or unexplained weight loss, which can point to infection or inflammation
- Neoplasm, meaning a history of cancer, since some cancers spread to the brain
- Neurologic deficit or a change in consciousness, such as weakness or confusion
- Onset that is sudden or abrupt, the so-called thunderclap headache that peaks within seconds to a minute
- Older age at onset, generally after 65, though some clinicians use 50 for a wider safety margin
- Pattern change, or a genuinely new type of headache unlike your usual ones
- Positional headache, one that clearly depends on whether you sit, stand, or lie down
- Precipitated by sneezing, coughing, or exercise
- Papilledema, meaning swelling of the optic disc that a clinician can see on eye examination
- Progressive headache, or an unusual, steadily worsening, atypical presentation
The list is rounded out by five further flags: pregnancy or the period just after it, a painful eye with autonomic features, onset after head trauma, a compromised immune system such as in HIV, and painkiller overuse. One small point of accuracy. The validated list is SNNOOP10. A claimed "SNNOOP12" update did not hold up when we checked it against the source, so we do not cite it. Of all these, a sudden thunderclap headache is the one that warrants emergency assessment without delay.
How migraine is actually treated
For a confirmed primary headache like migraine, treatment splits into two aims.
Acute treatment tries to stop an attack in progress and works best taken early. It usually starts with NSAIDs or paracetamol and steps up to triptans, such as sumatriptan and rizatriptan. Newer acute options include the gepants, such as ubrogepant and rimegepant, and lasmiditan. A key caution here is not to use acute medication too often, since frequent use can lead to medication-overuse headache.
Preventive treatment tries to reduce how often attacks come, and it is usually considered when attacks are frequent or particularly disabling. Conventional first-line choices include propranolol, amitriptyline, and topiramate. The newer preventives are the CGRP monoclonal antibodies, such as erenumab, fremanezumab, galcanezumab, and eptinezumab, along with two gepants, rimegepant and atogepant (Nature Reviews Disease Primers).
Two things are worth not overstating. The CGRP monoclonal antibodies are preventive medicines, not something you take to abort an attack in the moment, and their benefit is measured against placebo in trials. That benefit is real, but it is not a cure, and these drugs are usually tried after the conventional preventives. Behavioural and lifestyle approaches, like steady sleep, regular exercise, and stress management, work alongside medication rather than replacing it. If your attacks are frequent, disabling, or changing, that is a good reason to ask about a referral to someone who focuses on headache.
Sources for this piece are SNNOOP10, Do et al., Neurology 2019 and Nature Reviews Disease Primers.