How to recognize signs of stroke, cardiac arrest or heart attack

February 2023

If you think you or someone close to you is having a heart attack or stroke, it can be a confusing and scary situation. You may not know what to do, or the people around you—or the person in distress—may downplay or explain away the symptoms. However, it’s important to take action quickly because in these life-or-death situations, every moment counts. Read on to learn more about what heart attacks, cardiac arrests and strokes are, what are the signs and what to do.

The earlier you identify a problem, the better a person’s chance for survival.

1. Heart attack

What is a heart attack?

A heart attack happens when the oxygen-rich blood supply to the heart is cut off from part of the heart muscle. This is often caused by a blockage in an artery that supplies the heart with blood. Depending on how long the blood flow is cut off, the damage to the heart can range from mild to severe. 

Signs of a heart attack

There are a number of signs of a heart attack but not everyone will experience every sign. If you experience any of these signs, call 911 or get emergency help immediately. 

In addition to sweating, nausea, shortness of breath and light-headedness,

• Chest discomfort can feel like squeezing, fullness, pain, pressure, burning or heaviness 
• Upper body discomfort can be in neck, jaw, shoulder, arms or back
• you can also experience tightness, pressure, or burning, frequently accompanied by non-chest symptoms, such as dyspnea, fatigue, weakness, nausea, and discomfort in the upper back, shoulder, jaw, or arm

Women and heart attacks

Women can experience different signs than men during a heart attack. For example, women may or may not feel the classic chest pain, chest pressure or shooting pain down the arm, but they may experience:

• Shortness of breath
• Pressure or pain in the lower chest or upper abdomen (that women sometimes describe as tightness, pressure or burning)
• Dizziness, light-headedness or fainting
• Upper back pressure
• Extreme fatigue

What to do if you suspect a heart attack

1. Call 9-1-1 or your local emergency number 
2. Stop all activity. Sit or lie down. 
3. If it has been prescribed to you, take your normal dose of nitroglycerin.
4. Take ASA (aspirin). Chew and swallow one 325 mg tablet or two 81 mg tablets. 
5. Rest and wait for help. 
6. Keep a list of medications in your wallet and by your phone. Emergency personnel will want this information.

2. Cardiac arrest

What is a cardiac arrest?

Is cardiac arrest the same thing as a heart attack? Not exactly. A cardiac arrest is when the heart suddenly stops beating. This could be because of a heart attack, or because of another situation like severe physical trauma, poisoning, heart disease or drug use. It requires immediate medical attention. 

Signs of cardiac arrest

• Sudden collapse 
• Unresponsive to touch or sound
• Not breathing or is making gasping sounds

For those in cardiac arrest, survival drops significantly with every minute without CPR and use of an AED.

What to do if you witness a cardiac arrest?

1. Call 911 or your local emergency number right away. 
2. Get an AED (automated external defibrillator). Shout for someone to find an AED or ask the 911 operator where to find one nearby. These are portable machines available in public places (for example, an arena, theatre or community centre) that deliver an electrical shock to help restore a stopped heart’s rhythm.
3. Start CPR. While you’re waiting for the AED, or if one is not available, start CPR. Push hard and fast in the centre of the chest. Tip: the rhythm of the song “Stayin’ Alive” is a good guideline. 
4. Use the AED as soon as it’s available

Take action and don’t be afraid of doing it wrong—it’s the person’s best chance. The use of an AED and CPR more than doubles the chance of survival.

Be prepared!

Anyone can do CPR and use an AED: Watch these short videos from Heart & Stroke to learn how.

• Learn hands-only CPR in less than 90 seconds 
• Learn how to use an AED in less than 90 seconds

You don’t have to take a CPR course to perform CPR, but it can help you feel more confident in a crisis. Find more information and a course through Heart & Stroke.

Plus, read about people—who aren’t health professionals—who saved lives because they did CPR and/or used an AED

• Daughter saves father with CPR

3. Stroke

What is a stroke?

A stroke happens when blood stops flowing to any part of the brain, damaging blood cells. Most strokes are caused by a blockage or clot in a blood vessel in the brain (ischemic stroke). A stroke can also be caused when an artery in the brain breaks open (hemorrhagic stroke). Interrupted blood flow can cause brain cells to die leading to injury to the brain. 

Signs of a stroke

The acronym F.A.S.T. shows the most common signs of a stroke, but not everyone will experience all these signs:

Other, less common signs of stroke include:

• Vision changes Blurred or double vision
• Sudden severe headache Usually accompanied by other signs 
• Numbness Usually on one side of the body
• Problems with balance You may stumble, lose coordination or have trouble walking

What to do if you witness a stroke?

If you or anyone you are with experiences any of the signs of stroke, Call 9-1-1 or your local emergency number for immediate medical help.

The quicker the signs of stroke are recognized, and treatment is started, the greater the likelihood of a good recovery. Stroke is a medical emergency. If you experience any of these signs, call 9-1-1. Do not drive to the hospital. An ambulance will get you to the best hospital for stroke care.

Check out these real-life stories of people who knew the signs of stroke and got help quickly, as well as stroke-related resources from Heart & Stroke:

• How fast action saves lives
• Young girl takes action in stroke emergency
• Patient & Caregiver Resources from Canadian Stroke Best Practices

You could save a life by being more prepared to recognize the signs and symptoms and to act if you ever experience or witness someone in an emergency situation of heart attack, cardiac arrest or stroke. 

For more information or to revisit the signs listed above, bookmark this link from Heart & Stroke:

• Emergency Signs 

For more information on the specific conditions, check out these articles from Heart & Stroke:

• About heart attack 
• About cardiac arrest
• About stroke 

Signs can vary and may be different for everyone. If you experience any of these signs or are unsure, call 9-1-1 or your local emergency number immediately.