Headaches in the valley: what air quality has to do with it

Kathmandu has spent most of the last decade in a slow-moving conversation about air quality. From a neurology room, the conversation is more concrete: a measurable rise in headache complaints between November and April, peaking in the weeks when PM2.5 readings sit above 150.

The mechanism is well-studied. Fine particulate matter triggers low-grade inflammation in the trigeminal nerve pathways, which is the same system involved in migraine and tension-type headaches. People with no prior history start experiencing a dull, bilateral pressure that lifts on weekends spent outside the bowl of the valley.

What helps: a well-fitted N95 on commute days, an HEPA-filtered room at home that you actually sleep in, and consistent hydration. What doesn't help: stacking painkillers. Taking ibuprofen more than twice a week for headache reliably causes rebound headache — the cure becomes the cause.

If a headache changes character — sudden onset, worst-of-life intensity, fever, vision changes, or weakness on one side — that is an emergency, not a clinic visit. Go to A&E, and call us afterward.