When in doubt, call emergency services.

No — and nothing that works from typed symptoms should. Chest pain can be indigestion or a heart attack, and no text tool can tell them apart. What it does is teach you the signs that mean calling emergency services immediately, point you to the clinician-staffed advice lines that exist for the grey areas, and prepare everything else in advance.

Chest pain or pressure, difficulty breathing, stroke signs such as face drooping, arm weakness or slurred speech, severe bleeding, sudden severe headache unlike any before, confusion or unresponsiveness, seizures, severe allergic reaction, suspected poisoning or overdose, a head injury with vomiting or confusion, blue or grey lips, any fever in a baby under three months, bleeding or severe pain in pregnancy, and thoughts of harming yourself with a plan. Call rather than drive — treatment starts in the ambulance.

Never let that delay emergency care. In the United States, emergency departments are required to provide a medical screening examination regardless of ability to pay, and other countries have their own arrangements. Financial assistance, payment plans and billing corrections all exist — those conversations belong after treatment, not instead of it.

Not from averages, because costs vary enormously by country, insurer, plan, facility and network status. It uses your own numbers instead. With a $2,400 deductible remaining, the calculator shows urgent care at around $300 against an emergency visit at $2,720 — but once the deductible is met, that emergency visit drops to about $800. Useful for planning non-emergencies, never for deciding during one.

In some places, freestanding emergency centres look exactly like urgent care clinics from the street — similar signage, similar size, in a retail park — but bill at emergency rates. It's worth checking the type of each nearby facility now, while nothing is wrong, so you know which is which. The same goes for network status: a facility being in network doesn't guarantee every clinician treating you is.