15 Reasons to Go to the Emergency Room

Knowing when to go to the emergency room is one of the most important health literacy skills you can have. Go too often for minor issues and you waste hours, money, and space that genuinely critical patients need. Wait too long on something serious and the consequences can be permanent — or fatal.

Q: How do you know if something is a real emergency? A: The general rule is this: if you believe your life or someone else’s life is in danger, or that permanent harm could result from waiting, go to the ER. When in doubt, call 911 or your local emergency number — dispatchers are trained to help you make that decision in real time.

This list covers the situations that genuinely require emergency care — conditions where time matters, where urgent care or a primary care appointment is not enough, and where delay can change an outcome permanently. It is the serious companion to the situations that do not require an ER visit. Both pieces of knowledge matter equally.

1. Chest Pain or Pressure

Chest pain is one of the most critical emergency symptoms and should never be dismissed or waited out. While chest discomfort can have many causes — some benign — it is the hallmark symptom of a heart attack, which kills or permanently damages heart muscle in proportion to how long it goes untreated.

Go to the ER immediately if chest pain:

• Is crushing, squeezing, or pressure-like
• Radiates to your left arm, jaw, neck, or back
• Is accompanied by shortness of breath, nausea, or sweating
• Comes on suddenly at rest or during mild activity
• Does not resolve with rest within a few minutes

Do not drive yourself. Call 911. Paramedics can begin treatment en route, and hospitals can activate their cardiac response team before you arrive.

2. Signs of Stroke — Act FAST

A stroke occurs when blood supply to part of the brain is cut off. Brain cells begin dying within minutes. The faster treatment is received, the more brain function can be saved — which is why “time is brain” is not a slogan but a clinical fact.

Use the FAST acronym to recognize stroke symptoms:

• Face — sudden drooping or numbness on one side
• Arms — sudden weakness in one arm when both are raised
• Speech — sudden slurred speech, inability to find words, or confusion
• Time — call 911 immediately

Additional stroke symptoms include sudden severe headache with no known cause, sudden vision loss in one or both eyes, and sudden loss of balance or coordination. Do not wait to see if symptoms improve. Call 911.

3. Difficulty Breathing or Shortness of Breath

Sudden or severe shortness of breath — particularly at rest, or out of proportion to your level of activity — is a medical emergency. It can indicate a pulmonary embolism (blood clot in the lung), a severe asthma attack, heart failure, pneumothorax (collapsed lung), or a severe allergic reaction, among other causes.

Signs that breathing difficulty requires emergency care:

• Unable to complete a full sentence without stopping to breathe
• Lips or fingertips turning blue (cyanosis)
• Breathing becomes rapid and shallow at rest
• Sudden onset following a bee sting, food, or medication (possible anaphylaxis)
• Known asthma that is not responding to your rescue inhaler

4. Severe Allergic Reaction — Anaphylaxis

Anaphylaxis is a life-threatening allergic reaction that can cause the airway to swell shut within minutes. Common triggers include bee stings, peanuts, tree nuts, shellfish, certain medications, and latex.

Symptoms of anaphylaxis include:

• Throat tightening or difficulty swallowing
• Hives, itching, or skin flushing
• Swelling of the tongue, lips, or throat
• Wheezing or difficulty breathing
• Rapid, weak pulse
• Dizziness, lightheadedness, or loss of consciousness

If an epinephrine auto-injector (EpiPen) is available, use it immediately — then call 911 and go to the ER regardless, because anaphylaxis can have a biphasic reaction hours after the initial episode.

5. Loss of Consciousness or Unresponsiveness

If someone loses consciousness and cannot be roused, or becomes unresponsive, call 911 immediately. This applies whether the cause is apparent (a fall, a seizure) or unknown.

Loss of consciousness can result from cardiac arrest, stroke, severe hypoglycemia, drug overdose, severe head trauma, or other critical conditions. Many of these are time-sensitive — every minute without intervention reduces the chance of full recovery.

If the person is not breathing, begin CPR if you are trained and have someone else call 911 simultaneously.

6. Severe Head Injury or Trauma

Any significant head trauma — especially one involving loss of consciousness, confusion, vomiting, or worsening headache — requires emergency evaluation. Head injuries can cause internal bleeding that presents with a lucid interval — a period where the person seems fine — before symptoms rapidly deteriorate.

Go to the ER after head trauma if the person:

• Lost consciousness, even briefly
• Cannot remember the event
• Is confused, disoriented, or acting differently
• Vomits more than once after the injury
• Has a worsening headache
• Has unequal pupil sizes
• Has weakness, numbness, or difficulty speaking

A person who “seems fine” after a significant head impact can still have a life-threatening intracranial bleed — waiting to see if symptoms develop is not safe when the stakes are this high.

7. Uncontrolled Bleeding

If bleeding from a wound cannot be controlled with direct pressure after 10–15 minutes, or if the wound is deep, gaping, or spurting blood, emergency care is needed. Uncontrolled bleeding can lead to hemorrhagic shock, which is life-threatening.

Signs that a wound requires ER care:

• Bleeding does not slow after 10–15 minutes of firm, continuous direct pressure
• The wound is deep enough to see fat, muscle, or bone
• The wound is on the face, hand, joint, or genitals
• It was caused by a dirty or rusty object (tetanus risk)
• It was a bite — human or animal

Deep lacerations typically require sutures or staples to close properly, reduce infection risk, and minimize scarring. These cannot be adequately addressed at home.

8. Sudden Severe Headache — “The Worst of Your Life”

A sudden, extremely severe headache that comes on in seconds — often described as a thunderclap headache — is a medical emergency until proven otherwise. This type of headache can signal a ruptured brain aneurysm (subarachnoid hemorrhage), which has a very high mortality rate and requires immediate intervention.

This is distinct from a typical migraine. The hallmark feature is the sudden, explosive onset — peak intensity within 60 seconds of onset — and the severity, which patients consistently describe as the worst headache of their life.

Do not take pain medication and go to sleep. Go to the ER.

9. High Fever With Severe Symptoms

A fever alone is rarely a reason for an emergency room visit in adults. However, certain fever presentations require immediate evaluation:

• A fever above 103°F (39.4°C) in an adult that does not respond to over-the-counter medication
• Any fever in a baby under 3 months old — even a low-grade one
• Fever accompanied by stiff neck, severe headache, and light sensitivity (possible meningitis)
• Fever with confusion, altered mental status, or seizure
• Fever with a rash, particularly a non-blanching petechial rash
• Fever in an immunocompromised individual (cancer treatment, HIV, organ transplant)

10. Suspected Poisoning or Overdose

If you suspect someone has ingested a toxic substance — whether accidental (a child who ate medication) or intentional (drug overdose) — call Poison Control (1-800-222-1222 in the U.S.) immediately and follow their guidance, which often includes going to the ER.

Do not induce vomiting unless specifically instructed by Poison Control, as this can cause additional harm with certain substances. Bring the substance, packaging, or container to the ER so clinicians know exactly what was ingested.

For opioid overdose, if naloxone (Narcan) is available, administer it immediately — then call 911. Naloxone reverses opioid overdose temporarily but wears off, and the person still needs emergency medical evaluation.

11. Severe Abdominal Pain

Not all abdominal pain is an emergency — but certain presentations are. Sudden, severe abdominal pain, especially pain that is constant rather than cramping, can indicate a surgical emergency such as appendicitis, a ruptured ectopic pregnancy, a bowel obstruction, or a ruptured abdominal aortic aneurysm.

Go to the ER for abdominal pain that:

• Is sudden and severe
• Is concentrated in the lower right abdomen (possible appendicitis)
• Is accompanied by a rigid, board-like abdomen
• Comes with fever, chills, and vomiting
• Is in a woman of reproductive age with potential pregnancy (ectopic pregnancy)
• Is in an older adult or a person with cardiovascular disease

12. Broken Bones or Dislocations

Suspected fractures — particularly of the spine, pelvis, femur, or any bone following high-impact trauma — require emergency evaluation. A spinal injury that is moved incorrectly before immobilization can cause or worsen paralysis.

Dislocations of major joints (shoulder, hip, knee) are also emergency presentations — they cause significant pain, can trap blood vessels or nerves, and require prompt reduction.

For minor limb fractures in a stable adult, urgent care is sometimes sufficient. When in doubt about severity, or when trauma was significant, the ER is the safer choice.

13. Stroke-Like Symptoms Even If They Resolve

A transient ischemic attack (TIA) — sometimes called a mini-stroke — produces stroke-like symptoms that resolve within minutes to hours. It is a critical warning sign that a full stroke may be imminent, with the highest risk in the 24–48 hours immediately following a TIA.

If stroke symptoms occur and then resolve, do not assume the danger has passed. Go to the ER immediately. A TIA requires urgent imaging, evaluation, and often medication to prevent the full stroke that may otherwise follow.

14. Mental Health Crisis Involving Risk to Self or Others

A mental health emergency — including active suicidal ideation with a plan or intent, a psychotic break involving danger to self or others, or a severe overdose in the context of a mental health crisis — warrants emergency evaluation.

Emergency rooms have mental health crisis resources, can provide stabilization, and can connect individuals with inpatient psychiatric care when needed. If someone is in immediate danger of harming themselves or others, call 911.

Mental health emergencies are real emergencies — they belong in the same category as physical crises, and they deserve the same urgency and absence of stigma.

15. Any Situation Where Your Instinct Says Something Is Seriously Wrong

Medicine acknowledges the role of instinct. Patients and caregivers who say “something is just wrong — they don’t seem right” are often correct before any specific symptom can be named. This is particularly true for parents observing their children, and for caregivers of elderly or medically complex individuals.

If you cannot articulate exactly what is wrong but something feels seriously off — a change in behavior, a look in someone’s eyes, a feeling that you cannot explain — that instinct is worth acting on. Call 911 or go to the ER. You can always be wrong in the direction of caution. You cannot undo waiting too long.

Knowing when to seek emergency care is one of the most practical and potentially life-saving pieces of health literacy available to any adult. For those caring for aging relatives, understanding the signs your elderly parent needs help extends this same vigilance into daily caregiving — because many of the conditions on this list present differently in older adults and are easier to miss without deliberate attention.