Some symptoms are "call 911 immediately," not "ask AI." If you have any of these, stop using AI and get emergency help. An AI cannot assess an emergency remotely, cannot examine you, and cannot see how sick you look. When in doubt, call 911 (or your local emergency number).
Cardiac (heart)
Also call 911 for chest pain over 15 minutes; chest pain with cardiac risk factors (family history, high blood pressure or cholesterol, diabetes, smoking); sudden severe fatigue with chest discomfort; or an irregular heartbeat with lightheadedness. Women and people with diabetes may present atypically, with fatigue, nausea, or back pain and no classic chest pain.
Neurological (brain and nerves)
Also emergent: "worst headache of my life" (thunderclap); sudden severe headache with stiff neck; sudden vision loss or double vision; sudden confusion or trouble understanding speech; sudden severe dizziness or loss of balance; a first-time or prolonged seizure; loss of consciousness; sudden one-sided weakness or numbness; trouble walking or coordinating.
Abdominal (belly)
Severe abdominal pain with fever; a rigid, board-like abdomen; abdominal pain in pregnancy (any trimester); vomiting blood or "coffee grounds" material; black tarry stools or bright red blood in stool; severe pain that suddenly improves (can signal a perforation); abdominal pain with lightheadedness or fainting.
Respiratory (breathing)
Cannot speak in full sentences; gasping for air; blue or gray lips, face, or nails; severe shortness of breath at rest; high-pitched breathing (stridor); using neck muscles to breathe; chest pain with shortness of breath; shortness of breath with leg swelling.
Children
Infants under 3 months: fever (100.4°F / 38°C or higher), not feeding, not responding normally, hard to wake, breathing problems, or blue/gray skin.
Any child: trouble breathing or rapid breathing; blue or gray lips/face; unresponsive or hard to wake; severe headache with stiff neck; seizure; signs of severe dehydration (no tears, no urine for 8+ hours, sunken eyes); severe abdominal pain; will not eat or drink.
Other critical red flags
Severe allergic reaction (anaphylaxis): trouble breathing or throat swelling; rapid swelling of face, lips, or tongue; widespread hives with breathing difficulty; sudden lightheadedness or fainting.
Trauma: bleeding that will not stop with pressure; suspected spinal injury; severe head trauma with loss of consciousness; deformed suspected fracture; deep wounds exposing bone or muscle.
Poisoning or overdose: loss of consciousness, trouble breathing, seizures, or confusion after an ingestion or exposure. (US Poison Control: 1-800-222-1222.)
Mental health emergency: thoughts of harming yourself or someone else, or a sudden break from reality. Call 911, or in the US call or text 988 (Suicide & Crisis Lifeline). You do not have to face it alone.
Back pain PLUS: new bowel or bladder problems, numbness in the groin or inner thighs, progressive or both-sided leg weakness, foot drop, or fever. This can be cauda equina syndrome, a surgical emergency, call 911 or go to the ER.
What AI cannot detect
Remotely, an AI cannot assess any of this: skin color (pale, gray, blue, mottled), facial distress, breathing effort, or level of consciousness; sweating, perfusion, capillary refill, or pulse quality; blood pressure, heart rate, respiratory rate, temperature, or oxygen saturation; or the clinical sense that someone "looks sick." If you have concerning symptoms and these are the things it admits it cannot see, get evaluated regardless of its general advice.
The decision rule
While waiting for 911
Do: stay calm; stay with the person; note the time symptoms started; gather medications and history; unlock the door; have someone flag the ambulance. Do not: give anything by mouth if consciousness is altered; leave the person alone; drive yourself with cardiac or stroke symptoms; or delay the call to "see if it gets better."