What Is a Silent Heart Attack?
Direct answer: A silent heart attack, also called a
silent myocardial infarction, is a heart attack that causes
mild, unusual, or no obvious symptoms. Possible warning signs include unusual
fatigue, shortness of breath, mild chest pressure, indigestion, nausea,
dizziness, sweating, or discomfort in the jaw, back, neck, or arm.
Suspected heart attack symptoms require immediate medical evaluation.
According to the American Heart Association, about 170,000 of the approximately 805,000 heart attacks that occur in the
United States each year are silent.
Watch: Silent Heart Attack Warning Signs
This short educational video reviews warning signs that can be easier to
overlook and explains when emergency action may be necessary.
TL;DR: What Should You Know About Silent Heart Attacks?
- Yes, you can have a heart attack without realizing it.
- About 170,000 of the approximately 805,000 U.S. heart attacks
each year are silent, according to the American Heart Association. - Silent heart attack symptoms may resemble
fatigue, indigestion, nausea, shortness of breath, or muscle discomfort. - Chest pain or pressure can still occur, even when symptoms
are mild. - Women may also experience symptoms such as
unusual fatigue, nausea, shortness of breath, back discomfort,
or jaw discomfort. - You cannot safely rule out a heart attack based on symptoms alone.
- Call 911 immediately if you think you or someone else
may be having a heart attack. - If the person becomes unresponsive and is not breathing normally,
call 911, begin CPR, and use an AED if available.
7 Possible Silent Heart Attack Symptoms
- Mild chest pressure or discomfort:
Pressure, squeezing, fullness, or discomfort that may be less dramatic
than expected. - Unusual fatigue:
Exhaustion or weakness that feels unexplained or abnormal. - Shortness of breath:
Difficulty breathing that may occur with or without chest discomfort. - Indigestion or nausea:
Heartburn-like discomfort, upset stomach, or nausea. - Jaw, neck, back, or arm discomfort:
Unexplained pain or discomfort outside the chest. - Dizziness or lightheadedness:
Feeling unexpectedly dizzy, weak, or faint. - Unexpected sweating:
Unexplained or cold sweating, particularly when it occurs with other symptoms.
These symptoms do not prove that someone is having a heart attack.
They are warning signs that may require urgent medical evaluation.
What Is a Silent Heart Attack?
A silent heart attack is a myocardial infarction that occurs
with symptoms that are absent, mild, unusual, or not recognized as a heart
attack when the event occurs.
The medical term is silent myocardial infarction.
The heart muscle can still experience injury. The word “silent” describes
how the heart attack presents, not how serious it is.
The American Heart Association reported in September 2026 that approximately
170,000 of the estimated 805,000 heart attacks occurring annually
in the United States are silent.
Recognizing a medical emergency is important, but knowing how to respond
if someone becomes unresponsive is also valuable. Learn more about
CPR and emergency response training in Houston from Health Street CPRologist.
Can You Have a Heart Attack and Not Know It?
Yes. A person can have a heart attack without recognizing
it at the time. Symptoms may be mild, unusual, or mistaken for fatigue,
indigestion, muscle discomfort, illness, or another condition.
Some people only learn that they may have experienced a previous heart attack
after an ECG, imaging test, or later medical evaluation identifies evidence
consistent with previous heart injury.
This is one reason new or unexplained symptoms should not automatically
be dismissed simply because they do not resemble dramatic chest pain.
What Are the 7 Possible Silent Heart Attack Symptoms?
1. Mild Chest Pressure or Discomfort
Not every heart attack begins with severe chest pain. A person may experience
pressure, squeezing, fullness, or discomfort that feels mild or comes and goes.
2. Unusual Fatigue
Unexpected exhaustion can be easy to dismiss. Someone may assume the fatigue
comes from work, stress, poor sleep, illness, or aging when another cause
may be responsible.
3. Shortness of Breath
Difficulty breathing can occur with or without chest discomfort and is an
established heart attack warning sign.
4. Indigestion, Heartburn-Like Discomfort, or Nausea
Some heart attack symptoms can resemble gastrointestinal discomfort.
The American Heart Association includes nausea and stomach-related discomfort
among possible heart attack warning signs.
5. Jaw, Neck, Back, or Arm Discomfort
Heart attack discomfort is not necessarily limited to the chest. Pain or
discomfort can occur in the arms, back, neck, jaw, or stomach.
6. Dizziness or Lightheadedness
Unexpected dizziness or lightheadedness may occur alongside other heart
attack symptoms.
7. Unexpected Sweating
Cold or unexplained sweating may also occur during a heart attack.
One isolated symptom does not diagnose a heart attack, but combinations of
unexplained symptoms should not be ignored.
What Does a Silent Heart Attack Feel Like?
A silent heart attack may feel like mild chest pressure, unusual
fatigue, shortness of breath, indigestion, nausea, dizziness, sweating,
or discomfort in the jaw, neck, back, or arm.
Symptoms may feel less severe than the dramatic chest pain commonly associated
with heart attacks. They may also come and go, which makes self-diagnosis
unreliable.
What Are Silent Heart Attack Symptoms in Women?
Women can experience chest pain or discomfort during a heart attack.
The American Heart Association states that chest discomfort remains the most
common heart attack symptom in women, but other symptoms can occur.
Possible heart attack symptoms in women can include:
- Chest pain, pressure, or discomfort
- Shortness of breath
- Nausea or vomiting
- Unusual fatigue or weakness
- Back discomfort
- Shoulder discomfort
- Jaw pain
- Lightheadedness
- Upset stomach
These symptoms may sometimes be mistaken for reflux, illness, stress,
muscle pain, or other conditions.
Read the American Heart Association guidance on heart attack symptoms in women for additional information.
Can Indigestion Feel Like a Heart Attack?
Yes. Heart attack symptoms can sometimes resemble indigestion,
heartburn, nausea, or upper-abdominal discomfort.
A person cannot reliably determine the cause of new chest or upper-abdominal
discomfort at home based on symptoms alone.
If discomfort is new, unexplained, persistent, or accompanied by shortness
of breath, sweating, nausea, dizziness, weakness, chest discomfort, or
upper-body pain, seek emergency medical help.
How Is a Silent Heart Attack Detected?
A healthcare professional may evaluate a suspected current or previous
heart attack using the patient’s symptoms, medical history, physical
examination, and appropriate cardiac testing.
Depending on the clinical situation, testing may include:
- Electrocardiogram (ECG or EKG)
- Cardiac troponin blood testing
- Echocardiogram
- Coronary angiography
- Cardiac CT
- Cardiac MRI
- Other cardiac testing when clinically appropriate
Evidence consistent with a previous silent heart attack may sometimes be
identified after the original event.
When Should You Call 911 for Heart Attack Symptoms?
Call 911 if you think you or another person may be experiencing
a heart attack, even when you are not certain.
Do not wait for symptoms to become severe or attempt to rule out a heart
attack at home. Emergency medical services can begin assessment and
appropriate care during transport.
For additional warning-sign information, review the
American Heart Association heart attack warning signs.
Heart Attack vs. Cardiac Arrest: When Is CPR Needed?
A heart attack and cardiac arrest are not the same emergency.
A heart attack occurs when blood flow to part of the heart muscle is severely
reduced or blocked. Cardiac arrest occurs when the heart suddenly stops
effectively pumping blood.
A person experiencing a heart attack may still be conscious and breathing.
CPR is not performed simply because someone reports heart attack symptoms.
If the person becomes unresponsive and is not breathing normally,
call 911, begin CPR, and use an AED as soon as one is available.
Health Street offers CPR, AED, and First Aid classes in Houstonfor people who want hands-on emergency-response training.
Not sure which course you need? Read Do I Need CPR, BLS, AED, or First Aid?
for a breakdown of common certification options.
Frequently Asked Questions About Silent Heart Attacks
Can you have a heart attack and not know it?
Yes. A silent heart attack, or silent myocardial infarction,
may cause symptoms that are absent, mild, unusual, or not recognized as a
heart attack when they occur.
What does a silent heart attack feel like?
A silent heart attack may feel like mild chest pressure, unusual fatigue,
shortness of breath, indigestion, nausea, dizziness, sweating, or discomfort
in the jaw, neck, back, or arm.
What are the warning signs of a silent heart attack?
Possible warning signs include mild chest discomfort, unusual fatigue,
shortness of breath, nausea or indigestion, jaw or back discomfort,
dizziness, and unexplained sweating.
Are silent heart attacks dangerous?
Yes. “Silent” describes how the heart attack presents.
It does not mean the event is harmless. Heart muscle injury can still occur.
Are silent heart attack symptoms different in women?
Women can experience chest discomfort, but heart attack symptoms may also
include shortness of breath, nausea, unusual fatigue, back or shoulder
discomfort, jaw pain, lightheadedness, or upset stomach.
Can indigestion be a sign of a heart attack?
Yes. Heart attack symptoms can sometimes resemble indigestion or heartburn.
New or unexplained discomfort, particularly when combined with other warning
signs, should not be self-diagnosed at home.
Should you perform CPR on someone having a heart attack?
Not simply because the person has heart attack symptoms.
If the person becomes unresponsive and is not breathing normally, call 911,
begin CPR, and use an AED if one is available.
Learn CPR and AED Skills in Houston
Recognizing a medical emergency is one part of being prepared. Knowing what
to do if someone becomes unresponsive and stops breathing normally is another.
Health Street CPRologist provides American Heart Association CPR training in Houston,
including CPR, AED, First Aid, BLS, ACLS, PALS, NRP, and other
emergency-response training.
Individuals, parents, caregivers, teachers, coaches, and community members
can review CPR, AED, and First Aid class options in Houston.
Healthcare professionals who need advanced or healthcare-provider
certification can explore Health Street’s Houston CPR training center and available AHA courses.
Businesses, schools, churches, healthcare facilities, and other organizations
can also learn about on-site CPR and First Aid training in Houston.
If your employer or school simply told you to “get CPR certified,” use our CPR, BLS, AED, and First Aid class guide
to understand which course may fit your requirements.
Health Street CPRologist
1710 S. Dairy Ashford Rd., Suite #207Houston, TX 77077
Phone: (281) 920-9490
Email: info@cprologist.com
Medical Sources
About the Author
Written by Leah F., Operations Director at Health Street CPRologist
Leah supports American Heart Association course operations, student
registration workflows, certification support, instructor coordination,
and healthcare education content for Health Street CPRologist in Houston,
Texas. Her work supports CPR, BLS, ACLS, PALS, NRP, Heartsaver, First Aid,
AED, and Spanish-language training programs for healthcare professionals,
employers, students, and community members.
