Recognizing an Emergency
The symptoms that mean calling 911 rather than waiting.
Last revised
Key takeaways
- Always 911: chest pain, stroke signs, severe breathlessness, heavy bleeding, unconsciousness
- F.A.S.T.: Face drooping, Arm weakness, Speech difficulty, Time to call 911
- Most useful single change: Call 911 if you think it might be one of these; that is the right threshold.
- Commonest mistake: Driving yourself or someone else with a suspected heart attack or stroke.
- See a doctor if any of the signs under "When to get help" below apply to you.
Why it matters
In the conditions where minutes matter, delay is the main factor in outcome, and most delay is spent deciding whether to call.
The numbers, in one place
| Measure | Figure |
|---|---|
| Always 911 | chest pain, stroke signs, severe breathlessness, heavy bleeding, unconsciousness |
| F.A.S.T. | Face drooping, Arm weakness, Speech difficulty, Time to call 911 |
| Rash that does not fade when pressed, with fever | call 911; do not wait to see if it changes |
| Poisoning | Poison Control at 1-800-222-1222; call 911 if the person is unconscious, having a seizure or struggling to breathe |
| Text to 911 | available in many areas if you cannot speak safely |
What helps
- Call 911 if you think it might be one of these; that is the right threshold
- Put the phone on speaker so you can follow the dispatcher's instructions
- Unlock the door and put pets away if you can
- Know your address or location before you call
What to avoid
- Driving yourself or someone else with a suspected heart attack or stroke
- Waiting to see whether symptoms settle
- Hanging up before the dispatcher tells you to
In depth
Most medical emergencies share a common feature: something essential is failing. The airway may be blocked, breathing may be inadequate, the heart may not be pumping enough blood, or the brain may be losing its blood supply. These systems have little reserve, so damage builds by the minute. That is why the time between the first symptom and the first treatment is often the biggest single factor in how someone recovers.
Studies of heart attack and stroke consistently show that much of the delay happens before anyone calls for help. People hope symptoms will pass, worry about overreacting, call a relative first or try to drive to the hospital. Each step feels reasonable in the moment, but together they can cost the treatment window. Dispatchers and emergency teams would far rather attend a false alarm than arrive too late.
Calling 911 does more than bring an ambulance. The dispatcher can coach you through CPR, bleeding control or choking care while help is on the way. Paramedics can begin treatment at the scene, perform tests such as an ECG, and alert the right hospital so that a stroke or heart team is ready when you arrive. That head start is lost when someone arrives by car.
Signs and symptoms
- Chest pain, pressure or tightness, especially with sweating, nausea or breathlessness
- Sudden weakness, numbness or drooping on one side of the face or body
- Struggling to breathe, unable to speak in full sentences, or lips turning blue
- Unresponsiveness, or a person who cannot be woken normally
- A seizure lasting more than a few minutes, or one that happens again before recovery
- Heavy bleeding that does not stop with firm pressure
- Sudden, severe headache described as the worst ever
Causes and risk factors
- Heart attack and cardiac arrest
- Stroke and other bleeding inside the skull
- Severe allergic reactions
- Serious injury, including falls, crashes and burns
- Overwhelming infection leading to sepsis
- Poisoning and overdose
- Severe asthma or other breathing emergencies
How it is checked
When you call 911, the dispatcher follows a structured set of questions to judge how urgent the situation is and which resources to send. Answer simply and stay on the line. Expect to be asked your exact location first, then what happened, whether the person is awake and whether they are breathing normally. Cell phone location can be imprecise, so give the address, cross streets or landmarks.
At the ER, patients are triaged, meaning they are seen in order of medical urgency rather than arrival time. Someone with chest pain or stroke symptoms will be seen ahead of someone with a sprained ankle. Under federal law, ERs must provide a medical screening exam and stabilizing care to anyone who needs it, regardless of insurance or ability to pay.
Related topics
- Heart Attack Symptoms: What the Evidence Actually Says (Heart Health)
- Workplace First Aid: Sorting the Evidence From the Noise (Workplace Health)
- Stroke: What Published Guidance Supports (Brain Health)
- What the Guidance Really Says About When to Go to the ER (Using Health Services)
Where to go next
- Your Questions About Recognizing an Emergency, Answered
- Recognizing an Emergency at a Glance
- Emergency Care: The Complete Guide
- CPR and Defibrillation: What the Evidence Actually Says
- Choking: What the Evidence Actually Says
When to get help
Call 911 for chest pain or pressure lasting more than a few minutes, sudden weakness or numbness on one side, facial drooping, difficulty speaking, severe breathlessness, heavy bleeding, a seizure that does not stop, unconsciousness, a rash that does not fade when pressed, or signs of a severe allergic reaction. For problems that are urgent but not life-threatening, call your doctor's office or go to urgent care.
Where this comes from
- American College of Emergency Physicians — Know When to Go
- American Stroke Association — Stroke Symptoms
- Poison Control — Get Help
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.