Angina and heart attack both present with pressure and pain in the chest and pain in the arm, shoulder, neck, back or jaw. Stable angina generally has triggers that are predictable, but unstable angina does not, making distinguishing between the two disorders difficult, as stated by WebMD.
Angina is a temporary pressure or pain in the chest that results from insufficient oxygen to the heart muscle. When the arteries sending oxygen and blood to the heart have narrowed or developed a blockage, angina can result. Intense exertion, emotion, temperature extremes or a heavy meal can lead to angina. When it is stable, people can identify triggers that usually cause the sensations, and rest or prescribed nitroglycerin relieves the symptoms, as noted by WebMD.
The difference between unstable angina (meaning that the chest pain can come even without much exertion or any of the other triggers) and stable angina is that rest and medication do not alleviate the symptoms. If the chest pain does not resolve after taking nitroglycerin, a heart attack may be in progress, and it is time to seek emergency medical attention by calling 911. People who are experiencing chest pain for the very first time should call 911 as a precaution, as stated by WebMD