Basic Life Support Exam Answers: 25 Questions You Need to Know
So you're studying for your BLS certification exam. Maybe you're a nursing student, an EMT fresh out of training, or a healthcare worker who needs to renew. Either way, you're probably looking for practice questions that actually help you understand the material — not just memorize answers Simple, but easy to overlook..
Here's the thing about the BLS exam: it's straightforward if you understand the why behind the protocols. The American Heart Association updates these guidelines regularly, and what worked five years ago might not be correct today.
I've put together 25 representative questions that cover the core concepts you'll see on your exam. But more importantly, I've included explanations so you know why each answer is right. That's what actually sticks It's one of those things that adds up..
What Is the Basic Life Support Exam?
The BLS exam is the certification test healthcare providers take to demonstrate competency in life-saving techniques. It's based on American Heart Association guidelines and covers CPR, AED use, and choking response for adults, children, and infants It's one of those things that adds up..
You'll take this exam if you're:
- A nurse, doctor, or medical student
- An EMT or paramedic
- A dental professional
- A fitness trainer working in a facility with an AED
- Anyone required to maintain BLS certification for their job
The exam is typically taken online or in person after completing a BLS provider course. It includes both a written (or oral) test and a hands-on skills demonstration. This article focuses on the written portion — the knowledge test that accompanies the practical skills.
Why BLS Certification Matters
Here's what most people miss: BLS isn't just about passing a test. You're learning skills that save lives outside the hospital, too. Cardiac arrest can happen anywhere — at a gym, in a restaurant, at a child's soccer game.
The statistics are sobering. Survival rates for out-of-hospital cardiac arrest hover around 10%, but effective bystander CPR can double or even triple those odds. Worth adding: that's not abstract. That's real people walking around today because someone knew what to do But it adds up..
Beyond the humanitarian angle, BLS certification is often a job requirement. Healthcare facilities won't let you work without it. And if you let your certification lapse, you might find yourself suddenly ineligible for positions you applied for Worth keeping that in mind..
So yes, you need to pass this exam. And more importantly, you need to actually understand the material It's one of those things that adds up..
25 Basic Life Support Exam Questions and Answers
Here are 25 questions covering the key content areas. This leads to read through them carefully, then check your answers. I've included explanations for each one.
1. What is the correct compression-to-breath ratio for adult CPR when performed by a single rescuer?
Answer: 30:2
When you're performing CPR on an adult alone, you give 30 compressions followed by 2 rescue breaths. This ratio applies whether you're using a barrier device or doing mouth-to-mouth. The compressions do the heavy lifting — they circulate blood throughout the body when the heart can't do it itself Took long enough..
2. At what depth should chest compressions be performed on an adult?
Answer: At least 2 inches (5 cm)
You need to compress the chest at least 2 inches deep on an adult. This isn't a suggestion — it's the minimum effective depth. Pushing harder is better than pushing too soft. Shallow compressions don't generate adequate blood flow And that's really what it comes down to..
3. What is the recommended compression rate per minute for adult CPR?
Answer: 100 to 120 compressions per minute
The sweet spot is between 100 and 120 compressions per minute. Going faster than 120 actually reduces effectiveness because you don't allow enough time for the chest to fully recoil. The classic tempo to match is "Stayin' Alive" by the Bee Gees Which is the point..
4. When performing CPR on an infant (under 1 year), what technique should you use for chest compressions?
Answer: Two fingers placed just below the nipple line
For infants, use two fingers placed on the breastbone just below the nipple line. On the flip side, don't use the heel of your hand like you would for adults — you can easily compress too deeply and cause injury. Plus, the depth for infants is about 1. 5 inches (4 cm).
5. What is the compression-to-breath ratio for infant CPR?
Answer: 30:2
It's the same ratio as adults: 30 compressions to 2 breaths. The technique differs, but the ratio stays consistent across age groups for single-rescuer CPR.
6. A person is unresponsive, not breathing, and has no pulse. What should you do first?
Answer: Begin CPR immediately and have someone call 911 (or call 911 yourself if alone)
The priority is starting chest compressions immediately. Day to day, time is brain — every minute without CPR decreases survival chances by about 10%. Think about it: if you're alone, you should call 911 before starting CPR (or use a phone on speaker while starting). If someone else is present, have them call 911 while you begin CPR Turns out it matters..
7. What does the "A" stand for in the ABCs of CPR?
Answer: Airway
The ABCs are Airway, Breathing, and Circulation. Worth adding: you first open the airway (usually with a head tilt-chin lift), then check for breathing, then provide chest compressions for circulation. Some newer protocols highlight CAB (Circulation first), but understanding the concept matters more than the exact order Small thing, real impact..
8. What is the proper technique for opening an unresponsive person's airway?
Answer: Head tilt-chin lift
Place one hand on the forehead and gently tilt the head back. With the other hand, lift the chin upward. Plus, this moves the tongue away from the back of the throat and opens the airway. Be careful not to tilt too far if you suspect a neck injury — in that case, use a jaw-thrust maneuver instead.
9. When should you use an AED?
Answer: As soon as one is available after starting CPR
You should begin CPR immediately and continue until an AED arrives. Once the AED is available, turn it on and follow the voice prompts. The AED will analyze the heart rhythm and tell you whether to deliver a shock. Don't stop CPR while waiting for the AED or while setting it up.
10. What should you do immediately after delivering a shock with an AED?
Answer: Resume CPR immediately, starting with chest compressions
The AED will tell you to stand clear while it analyzes and potentially shocks. And immediately after the shock (or if "no shock advised"), resume CPR starting with chest compressions. Don't wait to check for a pulse — just start compressing. The AED will tell you when to stop and re-analyze That's the part that actually makes a difference. Took long enough..
11. A person is choking on food and can cough forcefully. What should you do?
Answer: Encourage them to continue coughing
If someone can cough, speak, or breathe, they're not experiencing a complete airway obstruction. In real terms, encourage them to keep coughing — it's their body's way of trying to clear the object. Stay with them and be ready to help if the situation worsens.
12. A person is choking and cannot breathe, speak, or cough. What should you do?
Answer: Perform the Heimlich maneuver (abdominal thrusts)
For a conscious adult or child with a complete airway obstruction, deliver abdominal thrusts (the Heimlich maneuver). Stand behind them, wrap your arms around their waist, and make a fist above their navel. Pull upward and inward with quick thrusts. For pregnant individuals or obese patients, chest thrusts are recommended Simple, but easy to overlook..
13. How do you perform back blows for an infant who is choking?
Answer: Hold the infant face-down on your forearm and deliver 5 firm back blows between the shoulder blades
Support the infant's head with your hand while holding them face-down along your forearm. Deliver 5 firm back blows using the heel of your hand between the shoulder blades. Then turn the infant face-up and give 5 chest thrusts using two fingers.
14. What is the sequence for treating a choking infant?
Answer: 5 back blows, then 5 chest thrusts, repeat
Alternate between 5 back blows and 5 chest thrusts until the object is expelled or the infant becomes unresponsive. If the infant becomes unresponsive, begin infant CPR and have someone call 911.
15. When performing two-rescuer CPR on an adult, what is the compression-to-breath ratio?
Answer: 30:2
Even with two rescuers, the ratio stays at 30:2. Which means one person performs compressions while the other maintains the airway and delivers breaths. The rescuers should switch positions every 2 minutes (or after 5 cycles) to prevent fatigue Worth knowing..
16. What is the recommended hand position for adult chest compressions?
Answer: Heel of one hand on the center of the chest (lower half of the breastbone), other hand on top
Place the heel of one hand on the center of the chest — specifically on the lower half of the breastbone (the sternum). Place your other hand on top and interlock your fingers. Keep your arms straight and use your body weight to compress But it adds up..
Most guides skip this. Don't.
17. How often should rescuers switch roles during CPR to prevent fatigue?
Answer: Every 2 minutes (or every 5 cycles of 30:2)
Rescuers should switch approximately every 2 minutes, which is about 5 cycles of 30:2. Think about it: fatigue leads to ineffective compressions, so switching regularly is crucial. The transition should be smooth — the new compressor should be in position before the previous one stops.
18. What is the "chain of survival" for adult cardiac arrest?
Answer: Recognition and calling for help, early CPR, rapid defibrillation, effective advanced life support, and post-cardiac arrest care
The AHA's chain of survival has five links: immediate recognition and calling 911, early CPR, rapid defibrillation, effective advanced life support, and integrated post-cardiac arrest care. Every link is critical — skip one and survival chances drop significantly Small thing, real impact..
19. What should you do if you're uncertain whether a pulse is present in an unresponsive adult?
Answer: Begin CPR
If you can't definitively feel a pulse within 10 seconds, start CPR. It's better to perform CPR on someone who has a pulse than to delay CPR on someone in cardiac arrest. The risks of unnecessary CPR are far lower than the risks of not doing CPR when needed Small thing, real impact..
Quick note before moving on Small thing, real impact..
20. What is "hands-only" CPR and when is it appropriate?
Answer: Continuous chest compressions without rescue breaths, recommended for untrained bystanders or those unwilling to give breaths
Hands-only CPR involves continuous chest compressions at 100-120 per minute without rescue breaths. And it's recommended for untrained bystanders or those uncomfortable giving breaths. It's particularly effective in the first few minutes after cardiac arrest when there's still oxygen in the blood.
21. What is the correct compression depth for child CPR (ages 1 to puberty)?
Answer: About 2 inches (5 cm), or at least one-third the depth of the chest
For children, compress about 2 inches deep, or at least one-third of the chest diameter. Use one or two hands depending on the child's size — you should be able to see the chest fully recoil between compressions Turns out it matters..
22. What is the compression-to-breath ratio for child CPR with two rescuers?
Answer: 15:2
Here's where it differs from adult CPR. Which means when two trained rescuers are performing child CPR, the ratio is 15 compressions to 2 breaths. This provides more ventilations than single-rescuer CPR, which remains at 30:2.
23. When should you stop performing CPR?
Answer: When an AED arrives, when trained responders take over, when the person starts breathing normally, when you are too exhausted to continue, or when a qualified provider declares death
You should stop CPR when: an AED becomes available, trained emergency responders arrive and take over, the person starts breathing normally or shows obvious signs of life, you become too exhausted to continue effectively, or a qualified healthcare provider declares the person deceased.
24. What should you do if you find an unresponsive adult and are alone with no phone?
Answer: Perform CPR for about 2 minutes, then go call 911 and return
If you're alone with no phone immediately available, perform CPR for approximately 2 minutes (about 5 cycles) before leaving to call 911. This provides some circulation before the interruption. If there's any chance someone else is nearby, call out for help first.
25. What is the purpose of "early defibrillation" in cardiac arrest?
Answer: To restore a normal heart rhythm when the heart is in ventricular fibrillation or pulseless ventricular tachycardia
Many cardiac arrests begin with ventricular fibrillation (VFib) or pulseless ventricular tachycardia (VTach) — chaotic heart rhythms that can be stopped with an electrical shock. Defibrillation attempts to "reset" the heart so it can resume a normal rhythm. Every minute of delay in defibrillation reduces survival by about 7-10%.
Common Mistakes on the BLS Exam
Most people miss questions for a few predictable reasons:
Confusing ratios. The 30:2 ratio for single-rescuer adult and infant CPR is consistent, but two-rescuer child CPR is 15:2. That's the one that trips people up.
Forgetting compression depth. Remember: adults at least 2 inches, infants about 1.5 inches, children about 2 inches (or one-third chest depth) Which is the point..
Not understanding when to use the AED. Some test-takers think you should check for a pulse first, then find an AED. Wrong. Start CPR and get the AED as soon as possible. Don't waste time looking for one before starting compressions And it works..
Confusing complete vs. partial obstruction. If someone is coughing, they're not choking. Don't perform the Heimlich on someone who can cough — stay with them and encourage them to keep coughing And that's really what it comes down to..
Tips for Passing Your BLS Exam
Here's what actually works:
Take the full course. Don't just study the questions. The hands-on practice matters, and you'll understand the concepts better when you've done compressions on a manikin.
Know the 2020 or 2022 guidelines. The AHA updates recommendations periodically. Make sure your study materials are current. If you're taking a course, it should be using the latest guidelines Easy to understand, harder to ignore..
Understand the "why." Memorizing ratios helps, but if you understand why compressions come first (circulation is more immediately critical than ventilation in the first minutes), you'll answer curveball questions correctly Most people skip this — try not to..
Practice the sequence. Write out the steps for adult CPR, child CPR, and infant CPR. Compare them side by side. The similarities and differences will become clear That's the part that actually makes a difference..
Don't skip the choking section. It seems separate from CPR, but it's part of the exam and part of being a competent BLS provider.
Frequently Asked Questions
How many questions are on the actual BLS exam?
The written portion typically has 25 to 30 questions, though this varies by testing center and whether you're taking the exam online or in person. The questions are usually multiple-choice.
What score do you need to pass the BLS exam?
Most providers require a passing score of 84% or higher. Some allow 80%. Check with your specific certifying organization.
Can you fail the BLS exam?
Yes, you can fail. That said, most people pass. If you fail, you'll typically be allowed to retake the exam after reviewing the material. Some courses allow unlimited retakes within a certain timeframe Simple, but easy to overlook. Which is the point..
How long is BLS certification valid?
BLS certification is typically valid for two years. You'll need to recertify before it expires to maintain your credentials.
Is the BLS exam the same as the ACLS exam?
No. ACLS (Advanced Cardiovascular Life Support) is more advanced — it covers cardiac arrest management, medication, and team dynamics. BLS (Basic Life Support) is for healthcare providers and covers CPR, AED use, and choking. ACLS requires BLS certification as a prerequisite.
The Bottom Line
The BLS exam is manageable if you understand the core concepts. Focus on compression ratios, depth, and rates. Know when to use the AED and how to respond to choking. Understand the differences between adult, child, and infant protocols Worth keeping that in mind..
But here's what matters more than passing: you'll actually use this knowledge. Someone's life might depend on it. The exam is just proof that you can do it when it counts That's the whole idea..
Good luck. You've got this.
