BLS stands for Basic Life Support, a set of emergency skills that every nurse is expected to know and maintain throughout their career. It covers recognizing cardiac arrest, performing CPR, using an automated external defibrillator (AED), and clearing a blocked airway. BLS certification is typically required before starting clinical rotations in nursing school and remains a condition of employment at virtually every hospital and healthcare facility.
What BLS Covers
Basic Life Support is built around the earliest, most time-sensitive interventions for someone whose heart has stopped or who can’t breathe. The American Heart Association describes these as the first links in what it calls the “Chain of Survival,” the sequence of actions that gives a person in cardiac arrest the best chance of making it to more advanced care. The core skills include recognizing cardiac arrest, activating an emergency response, delivering high-quality chest compressions and rescue breaths, and using an AED to restore a normal heart rhythm.
BLS also covers choking emergencies, formally called foreign body airway obstruction. For a conscious adult who is choking, the protocol calls for repeated cycles of 5 back blows followed by 5 abdominal thrusts until the object comes out or the person becomes unresponsive. For someone in late pregnancy, or when you can’t get your arms around the person’s abdomen, chest thrusts replace abdominal thrusts. If the person loses consciousness, you transition immediately to CPR, starting with compressions and checking the mouth for a visible object before giving breaths.
The BLS Sequence Step by Step
Healthcare providers follow a specific algorithm. The sequence begins with verifying that the scene is safe, then checking for responsiveness. If the person doesn’t respond, you shout for nearby help and activate the emergency response system while sending someone to get an AED and emergency equipment. You then simultaneously look for normal breathing and check for a pulse. If there’s no pulse and the person isn’t breathing (or is only gasping), you begin CPR.
For adults, CPR follows a ratio of 30 chest compressions to 2 rescue breaths. Compressions should be at least 2 inches deep but no more than 2.4 inches, delivered at a rate of 100 to 120 per minute. Full chest recoil between compressions matters because it allows the heart to refill with blood. When an AED arrives, you apply the pads as quickly as possible without long interruptions to compressions, and the device analyzes the heart rhythm and tells you whether a shock is advised.
Why Nurses Need BLS Specifically
Nurses are often the first clinicians at the bedside when a patient deteriorates. On a hospital ward, the nurse who recognizes that a patient has stopped breathing or lost a pulse is the one who starts CPR and calls a code blue. Minutes pass before a full resuscitation team arrives, and the quality of compressions and early defibrillation during that window directly affects whether the patient survives. The 2025 AHA guidelines emphasize that high-quality basic life support is “foundational to improving outcomes,” meaning everything that follows, including medications and advanced airway management, works better when BLS is done well from the start.
Outside the hospital, nurses working in clinics, schools, long-term care facilities, or home health may encounter cardiac arrest with no crash cart nearby. BLS training prepares you to respond effectively with minimal equipment, using only your hands, a pocket mask, and an AED.
BLS vs. ACLS
BLS and ACLS (Advanced Cardiovascular Life Support) are often mentioned together, but they cover different levels of intervention. BLS focuses on CPR, AED use, rescue breathing, and choking relief. It requires no medications, no IV lines, and no advanced equipment. ACLS builds on top of BLS by adding advanced airway management, IV access, medication administration, and electrical therapies like cardioversion and transcutaneous pacing.
BLS courses are open to everyone but designed for healthcare providers and first responders. ACLS is specifically for clinicians: physicians, nurses, paramedics, respiratory therapists, and others who manage complex emergencies. Most bedside nurses in acute care settings hold both certifications, but BLS is the universal baseline. You’ll need BLS before you can take ACLS, and many nursing roles (outpatient clinics, public health, school nursing) require only BLS.
Certification and Renewal
BLS certification courses are offered by the American Heart Association and the American Red Cross, the two organizations most hospitals recognize. The course is typically completed in a few hours and includes both a written test and a hands-on skills check where you demonstrate compressions, ventilations, and AED use on a manikin. Certification is valid for two years, at which point you take a renewal course to stay current with any guideline updates.
One detail that catches some nurses off guard: BLS renewal does not count as continuing education for license renewal in many states. Texas, for example, explicitly excludes BLS and CPR from the activities that satisfy continuing education requirements. This means you need BLS to keep your job, but you’ll still need separate continuing education credits to renew your nursing license. Check your own state board’s rules, as policies vary.
What the Course Looks Like
If you’re preparing for your first BLS class, expect a mix of video instruction, group discussion, and hands-on practice. You’ll rotate through stations practicing compressions on adult, child, and infant manikins. The skills test requires you to perform a full CPR scenario, including recognizing arrest, calling for help, delivering compressions at the correct depth and rate, giving breaths, and using an AED. Most people pass on the first attempt, but instructors will let you retry specific stations if needed.
Many programs now offer a blended format: you complete the knowledge portion online at your own pace, then attend a shorter in-person session for the hands-on skills check. This can cut the classroom time roughly in half. Fully online BLS courses do exist, but most employers and nursing programs do not accept them because there’s no way to verify your physical technique without an in-person evaluation.