When to Go to the ER: Emergency Warning Signs Guide

A US guide to recognizing true emergencies, choosing between ER, urgent care, and telehealth, understanding triage, and knowing realistic costs and wait times.

By Symptom Advisory Editorial Team — last reviewed September 1, 2026 — 15 min read

Key Takeaways

• Call 911 for chest pain, stroke signs (use FAST), severe breathing trouble, uncontrolled bleeding, or a serious head injury.
• Stroke treatment works best within 3 to 4.5 hours of symptom onset, so acting fast preserves brain function, per the CDC.
• Urgent care suits same-day, non-life-threatening problems like sprains, minor cuts, and ear infections, at a fraction of ER cost.
• ER triage uses the 5-level Emergency Severity Index (ESI), so higher-acuity patients are seen before those who arrived earlier.
• A typical ER visit can run $1,500 to $3,000 or more before insurance, versus roughly $150 to $300 for urgent care in 2025.
• Call or text 988 for a suicide or mental health crisis; call 911 if there is immediate danger to life.
• EMTALA requires hospitals to screen and stabilize every ER patient regardless of ability to pay.
• Bring ID, insurance card, medication and allergy lists, and follow up with your primary care provider after any ER visit.

Deciding where to get care in an emergency can feel confusing. Should you call 911, drive to the emergency room, book an urgent care slot, or start a telehealth visit? Getting this decision right matters. Going to the emergency room (ER) for a problem that urgent care could handle means longer waits and a much bigger bill. But treating a true emergency like a minor problem can cost precious time when minutes matter, as with a heart attack or stroke.

This guide walks through the warning signs that call for immediate emergency care, how to tell an emergency from an urgent problem, what actually happens once you arrive at the ER, and what care typically costs in 2025 and 2026.

This article is for general education. It does not diagnose any condition. If you believe you or someone else is having a medical emergency, call 911 right away.

ER vs. Urgent Care vs. Telehealth: How to Decide

Think of care options on a spectrum based on how serious and how time-sensitive the problem is.

Call 911 or go to the ER when a symptom could be life-threatening or could cause permanent damage if not treated within minutes to hours. The Centers for Disease Control and Prevention (CDC) and the American College of Emergency Physicians (ACEP) both note that emergency departments are built to handle sudden, severe, and unpredictable conditions with imaging, labs, specialists, and resuscitation equipment on site around the clock.

Go to urgent care when a problem needs same-day attention but is not life-threatening, such as a sprained ankle, a minor cut that may need stitches, a urinary tract infection, an earache, or a low-grade fever without other red flags. Urgent care centers typically have shorter waits and lower costs than an ER, according to the Health Care Cost Institute (HCCI) and multiple insurer cost-comparison guides published in 2025.

Use telehealth or call your primary care provider for problems that do not need a hands-on exam right away, such as a medication refill question, mild cold symptoms, a rash without fever, or follow-up questions after a diagnosis. Telehealth cannot examine you physically, order emergency imaging, or run bloodwork on the spot, so it is not appropriate for anything that could be serious.

When in doubt about how urgent a symptom is, many health plans and hospital systems offer 24/7 nurse advice lines. Calling one is reasonable if you are unsure and the situation does not feel immediately life-threatening. If it does feel life-threatening, do not wait on hold. Call 911.

Red-Flag Symptoms by Body System

Emergency medicine organizations group warning signs by body system because different combinations of symptoms point to different urgent conditions. Below are patterns that ACEP, the American Heart Association (AHA), and the CDC identify as reasons to seek emergency care immediately.

Chest and Cardiac Symptoms

According to the AHA, seek emergency care for:

• Chest pain, pressure, squeezing, or fullness lasting more than a few minutes, or that goes away and comes back
• Pain or discomfort spreading to one or both arms, the back, neck, jaw, or stomach
• Shortness of breath with or without chest discomfort
• Breaking out in a cold sweat, nausea, or lightheadedness along with chest symptoms

Women are somewhat more likely than men to have heart attack symptoms without obvious chest pain, such as unusual fatigue, nausea, or back or jaw pain, per AHA patient materials. Any of these combinations warrants calling 911, not driving yourself.

Neurologic Symptoms and Stroke (Think FAST)

The CDC and AHA promote the FAST test to recognize stroke:

• F — Face drooping: One side of the face droops or feels numb
• A — Arm weakness: One arm drifts downward when both arms are raised
• S — Speech difficulty: Speech is slurred, or the person cannot repeat a simple sentence
• T — Time to call 911: If any of these signs are present, note the time symptoms started and call 911 immediately

Other stroke warning signs include sudden confusion, sudden trouble seeing in one or both eyes, sudden trouble walking, dizziness, loss of balance or coordination, and a sudden severe headache with no known cause. The CDC notes that treatments for ischemic stroke work best within the first three to four and a half hours after symptoms start, so acting fast genuinely saves brain tissue.

Breathing Problems

Seek emergency care for:

• Severe shortness of breath or the feeling of not being able to get enough air
• Blue or gray lips, face, or fingernails
• Wheezing or stridor (a high-pitched sound when breathing) that does not improve with a rescue inhaler
• Choking with an inability to cough, speak, or breathe

Abdominal and Digestive Symptoms

Seek emergency care for:

• Sudden, severe abdominal pain, especially if it is constant or gets worse quickly
• Abdominal pain with a rigid, board-like belly
• Vomiting blood or material that looks like coffee grounds
• Black, tarry, or bloody stools
• Severe pain with fever and inability to keep fluids down

Bleeding, Trauma, and Injury

Seek emergency care for:

• Bleeding that will not stop after 10 minutes of firm, direct pressure
• Any deep wound, especially on the face, hands, or over a joint
• A head injury with loss of consciousness, repeated vomiting, worsening headache, or confusion
• Suspected broken bones with visible deformity, or a bone that has broken through the skin
• Falls in older adults, even without obvious injury, since the CDC identifies falls as the leading cause of injury death in adults 65 and older

Pediatric Warning Signs

Call 911 or go to the ER for a child with:

• A fever above 100.4°F (38°C) in an infant younger than 3 months, per American Academy of Pediatrics (AAP) guidance
• Difficulty breathing, grunting, or ribs pulling in with each breath
• A seizure, especially a first-time seizure
• Lethargy, being very hard to wake, or not responding normally
• Signs of dehydration such as no wet diapers for 8 or more hours, no tears when crying, or a sunken soft spot
• A rash that does not fade when pressed, along with fever

Mental Health Crisis

A mental health emergency is just as real as a physical one. Seek immediate help for:

• Talking about wanting to die or suicide, or making a plan
• Severe agitation, paranoia, or loss of touch with reality
• Intent to harm oneself or someone else

In the United States, call or text 988 to reach the Suicide & Crisis Lifeline, available 24/7 and free and confidential, according to the Substance Abuse and Mental Health Services Administration (SAMHSA). If there is an immediate danger to life, call 911 or go to the nearest ER, which can provide psychiatric evaluation and safety planning.

Symptom-to-Destination Table

What Happens at Triage: Understanding ESI Levels

When you arrive at an ER, a nurse will assess you before you are seen by a doctor. This process is called triage, and it is not first-come, first-served. Most US emergency departments use the Emergency Severity Index (ESI), a five-level scale developed with support from the Agency for Healthcare Research and Quality (AHRQ):

• ESI Level 1: Requires immediate life-saving intervention (for example, cardiac arrest)
• ESI Level 2: High risk situation, severe pain or distress, or symptoms suggesting a serious problem developing quickly (for example, stroke symptoms, chest pain)
• ESI Level 3: Stable but needs multiple resources such as labs, imaging, and IV fluids
• ESI Level 4: Needs one resource (for example, an X-ray for a possible fracture)
• ESI Level 5: Needs no resources (for example, a medication refill or simple prescription)

This is why someone who arrived after you may be seen first: they may have a higher-acuity ESI level. Triage nurses reassess waiting patients periodically, so tell staff immediately if your symptoms change or worsen while you wait.

What to Bring to the ER

Having the following on hand can speed up your visit and improve accuracy of care:

• Photo ID and insurance card
• A list of current medications and doses, or the medications themselves
• A list of allergies, especially to medications
• Key medical history, including past surgeries and major diagnoses
• Emergency contact information
• For children: their pediatrician's name and immunization record if available
• A phone charger, since ER visits can take several hours

Do not delay care to gather these items. Paramedics and ER staff can work with verbal information if paperwork is not available.

Wait Times and Costs: What to Realistically Expect

Wait times and costs vary widely by region, hospital, insurance status, and how severe your triage level is. Here is a general comparison based on CDC National Hospital Ambulatory Medical Care Survey (NHAMCS) data and 2025 industry cost reporting from the Health Care Cost Institute (HCCI) and insurer resources.

A few realities worth knowing:

• Under the federal No Surprises Act, out-of-network emergency care must generally be billed at in-network cost-sharing rates, which limits (but does not eliminate) surprise billing for ER visits, according to the Centers for Medicare & Medicaid Services (CMS).
• Hospitals are required to screen and stabilize anyone who comes to the ER regardless of ability to pay, under the federal Emergency Medical Treatment and Labor Act (EMTALA), enforced by CMS.
• Ambulance transport is billed separately from the ER visit itself and can add a significant additional cost, which varies by locality and whether the ambulance service is in-network.
• Some insurers charge a higher copay for ER visits later found to be non-emergencies, so it is worth understanding your specific plan's ER policy, according to KFF research on employer health plans.

What Happens After You're Seen

Once a physician or advanced practice provider evaluates you, one of a few things typically happens:

• Discharge with instructions: You are stable enough to go home, often with a written after-visit summary, prescriptions, and instructions on when to return.
• Observation status: You stay in the ED or an observation unit for a period, often up to 24-48 hours, while the team monitors you or waits on test results.
• Admission: You are admitted to the hospital for ongoing treatment.
• Transfer: In rare cases, you may be transferred to another facility with specialized capabilities, such as a trauma center or stroke center.

Always follow up with your primary care provider within the timeframe the ER recommends, generally within a few days for most conditions. Bring your discharge paperwork to that visit. If new or worsening symptoms appear after discharge, especially any of the red-flag signs above, return to the ER or call 911 rather than waiting for a scheduled follow-up.

The Bottom Line

When a symptom matches any of the red-flag patterns above, especially chest pain, stroke symptoms, severe breathing trouble, uncontrolled bleeding, a serious head injury, or a mental health crisis, do not wait and do not drive yourself. Call 911. For everything else that needs same-day attention but is not life-threatening, urgent care or telehealth will usually get you seen faster and for far less money. When you are unsure, err on the side of caution and seek in-person evaluation. No article can replace an in-person medical assessment, and this guide is not a substitute for professional medical advice.

Practical Checklist

• Memorize stroke signs: FAST
• Know heart attack symptoms for both men and women
• Save Poison Control number: 1-800-222-1222
• Identify nearest ER and urgent care locations
• Learn pediatric emergency warning signs
• Prepare medical history summary for emergencies
• Know your medication list and allergies
• Understand when urgent care is appropriate

Frequently Asked Questions

How do I know if chest pain is a heart attack?

Heart attack chest pain typically feels like pressure or squeezing, may radiate to arm/jaw/back, worsens with exertion, and comes with shortness of breath or sweating. When in doubt, call 911.

What does FAST stand for in stroke recognition?

Face drooping, Arm weakness, Speech difficulty, Time to call 911. These are the most recognizable stroke warning signs.

When is a fever considered an emergency?

Fever over 100.4°F in infants under 3 months always requires ER evaluation. In adults, fever over 103°F or lasting more than 3 days warrants emergency assessment.

Should I drive to the ER or call 911?

Call 911 for life-threatening emergencies. Paramedics can begin treatment en route and alert the hospital. For urgent but non-life-threatening issues, driving or urgent care may be appropriate.

What should I tell the ER triage nurse?

Report what happened and when, current medications, allergies, medical history, pain level 1-10, and what treatments you have already tried.

Sources & References

1. Emergency Department Statistics — Centers for Disease Control link
2. Stroke Warning Signs — American Stroke Association link
3. Heart Attack Symptoms — American Heart Association link

Medical disclaimer

This article is health information for education only. It is not medical advice, a diagnosis or a treatment plan. In an emergency, call 911. Researched and drafted with AI-assisted tools and fact-checked by a human editor against the sources listed above. How we create our content.