If someone is choking but can still cough, speak, or breathe, encourage them to keep coughing — this is often the body's most effective way of clearing the airway on its own. Don't intervene further unless coughing stops being effective.
If a person cannot cough, speak, or breathe, lean them forward and give up to five firm back blows between the shoulder blades with the heel of your hand. If that doesn't clear the blockage, abdominal thrusts (standing behind the person, hands clasped above the navel, pulling inward and upward) can help dislodge the object — this technique is different and gentler for infants, who should receive back blows and chest thrusts instead, ideally after learning the technique from a trained provider.
Call for emergency help immediately if the person loses consciousness, and continue basic first aid until help arrives. If you have never been trained in these techniques, a local clinic, Red Cross chapter, or community health program can often provide a short, free or low-cost first aid course.
This information is a starting point, not a substitute for hands-on training — choking response is a skill that's much easier to perform correctly after practising it with a qualified instructor.