A heart attack occurs when blood flow to part of the heart is blocked, while cardiac arrest happens when the heart suddenly stops pumping blood effectively. Heart attack symptoms may include chest pain, breathlessness, sweating, nausea, or discomfort in the arm or jaw. Cardiac arrest often causes sudden collapse, unconsciousness, and abnormal or absent breathing. Both are medical emergencies that require immediate attention. Knowing the difference can help people respond quickly when symptoms appear. For ongoing heart care and expert evaluation, choosing a best cardiology hospital in Chennai can provide access to experienced specialists and appropriate cardiac treatment.