Nearly every page on this site has its own "when to call vs. go to the ER" guidance specific to that condition — this page pulls the most common cardiac symptoms together in one place, since knowing which bucket a symptom falls into is often the hardest part of a stressful moment. When in real doubt, especially with chest pain, err toward calling 911 — it's always the safer choice.
Chest Pain or Pressure
Go to the ER or call 911 if: new chest pain or pressure, especially with any of the following — spreading to your arm, neck, jaw, or back; shortness of breath; sweating; nausea; or lightheadedness. This combination is the classic pattern of a possible heart attack, and time matters — don't drive yourself, and don't "wait to see if it passes" with this specific combination.
Call your care team if: chest discomfort that's mild, clearly reproducible by pressing on the area (more likely musculoskeletal), or a pattern you've had evaluated before that feels the same as usual — but when in doubt, treat new chest pain as an emergency until proven otherwise.
Shortness of Breath
Go to the ER or call 911 if: sudden, severe shortness of breath; shortness of breath at rest; or shortness of breath with chest pain, fainting, or blue-tinged lips.
Call your care team if: shortness of breath that's gradually worsening over days, especially with weight gain or swelling (see below) — this pattern points toward fluid retention that needs prompt but not necessarily emergency attention (see Heart Failure).
Rapid Weight Gain or Swelling (Heart Failure Patients)
Call your care team if: a weight gain of 3+ lbs overnight or 5+ lbs in a week, or increasing swelling in your legs, ankles, or abdomen — these are classic early warning signs of fluid retention, and catching them early often prevents a hospitalization.
Go to the ER if: this is combined with significant shortness of breath, especially at rest or lying flat.
Palpitations (Racing, Skipping, or Fluttering Heart)
Call your care team if: new or increasing palpitations, even if brief and without other symptoms.
Go to the ER or call 911 if: palpitations with chest pain, fainting, or severe shortness of breath, or a very fast racing heart rate that doesn't resolve on its own. (See Palpitations & Arrhythmias for a fuller breakdown.)
Fainting or Near-Fainting
Go to the ER or call 911 if: fainting with no clear, benign trigger (like standing up too fast or being in a hot, crowded room), especially with chest pain, palpitations, or if it happened during exercise.
Call your care team if: a single fainting episode with a clear benign explanation, to discuss whether further evaluation is still warranted.
Very High Blood Pressure Reading
Go to the ER or call 911 if: a blood pressure reading above roughly 180/120 combined with symptoms like severe headache, chest pain, shortness of breath, vision changes, or difficulty speaking — a hypertensive emergency.
Call your care team if: a high reading without those symptoms — recheck it after resting, and report a consistent pattern of high readings. (See Taking Your Blood Pressure: Best Practices.)
A Single ICD Shock
Call your care team if: one shock that leaves you feeling stable afterward.
Go to the ER or call 911 if: multiple shocks in a short period, or a shock with ongoing chest pain, fainting, or shortness of breath. (See Living with a Pacemaker or ICD.)
Signs of Infection After a Procedure or Surgery
Call your care team if: mild redness or soreness at an incision or device site.
Go to the ER if: fever, spreading redness, warmth, drainage, or a wound that's opening up.
When You're Genuinely Unsure
If you've read through this page and still aren't sure which category your symptom falls into, that uncertainty itself is a reasonable reason to call — a nurse line or your care team can help you decide over the phone, and it's always appropriate to err toward more caution with anything involving the heart. Emergency departments and 911 dispatchers would always rather evaluate a symptom that turns out to be nothing than have someone wait too long with something serious.
Common Questions
Am I overreacting if I call 911 and it turns out to be nothing?
No — emergency responders and ER staff evaluate possible cardiac symptoms constantly, and a "false alarm" that turns out benign is a normal, expected part of appropriately cautious care, not a waste of anyone's time.
Should I drive myself to the ER for chest pain?
No — call 911 instead. Paramedics can begin treatment before you arrive and are prepared for the rare case that your condition worsens en route, which you can't manage while driving yourself.
What if I'm not sure if my symptom is 'cardiac enough' to call?
Call anyway, or use a nurse line if your care team has one — you don't need to self-diagnose before reaching out, that's exactly what the call is for.
Is it different for someone with a known heart condition versus someone without one?
The general thresholds above apply to everyone, but if you have a known condition (heart failure, a prior heart attack, a device), your care team may have given you specific, personalized guidance — follow that if it's more specific than the general guidance here.