If you saw someone suddenly collapse and become unresponsive, would you know the best way to save his life? Cardio-pulmonary resuscitation (CPR) can help in cases of heart attacks, near drowning or other times where someone’s breathing or heart beat has stopped. But the recommendations for how to administer CPR differ with the age and condition of the unconscious person.

Use these guidelines to make sure you’d know what to do if someone near you stops breathing.

Know the two types of CPR. Conventional CPR includes mouth-to-mouth breathing and chest compressions. Hands-only CPR uses just chest compressions. (The best way to learn CPR is by taking a class.)

Use conventional CPR for infants and children. Conventional CPR may be more beneficial for infants and children up to puberty, according to the American Heart Association. It is also recommended for:

  • unconscious teens or adults whom you did not see collapse
  • victims of drowning
  • victims of a drug overdose

Remember the ABCs. When performing conventional CPR, focus on airway, breathing and circulation.

  • Airway: Make sure the person is flat on his back. Then, to open the person’s airway, lift the chin up with one hand while pushing down on the forehead with the other. Take five to 10 seconds to check for breathing. If opening the airway does not stimulate breathing, start rescue breathing.
  • Breathing (rescue breathing): Keeping the person’s head tilted, pinch his nose shut with your thumb and forefinger. Inhale normally, then give two full breaths lasting one second each. Your mouth should create an airtight seal around the person’s mouth, and his or her chest should rise.
  • Circulation (chest compression): After giving two full breaths, kneel at the person’s side and place the heel of your hand on the sternum, which is above the notch in the center of the chest. Place your other hand on top of the first hand and lace your fingers together. Press down hard and fast, keeping your arms straight.
  • Use 30 chest compressions to every two breaths. Compress at the rate of about 100 times per minute.

Consider hands-only CPR for teens and adults. The 2010 American Heart Association guidelines recommend hands-only CPR, with just chest compressions, for teens or adults who have suddenly collapsed. A teen or adult who has collapsed will still have enough oxygen to support vital organs while someone provides continuous chest compressions to maintain blood flow.

  • Push hard and fast in the center of the chest. Compress the chest at least 2 inches.
  • Continue compressions. Compress at least 100 times per minute Do not stop unless breathing resumes or a trained responder arrives to take over.

Modify chest compressions for a pregnant woman. Make sure you compress the chest slightly higher on the sternum to adjust for the woman’s elevated diaphragm.Another person should push the victim’s uterus to her left side to relieve pressure on big veins while you administer CPR, according to the 2010 American Heart Association guidelines.

Any attempt at resuscitation is better than none. If you are not confident that you can provide conventional CPR with breaths and chest compressions, you should still administer hands-only CPR.Chest compressions alone can more than double the chances of survival in the case of sudden cardiac arrest, reports the American Heart Association. Even if an adult has collapsed for other reasons, hands-only CPR could help to stimulate a response from the person.