How to tell the difference between a heart attack and other pain
BMJ Group Medical Reference
Sometimes it's hard to tell whether the pain you're having is from a heart attack or something else. Here's a guide to some of the differences.
If you have any sort of chest pain and you think you could be having a heart attack, call 999 immediately.Chest pain (angina)
Angina is the name doctors use for a pain in your chest that you get when your heart muscle isn't getting enough oxygen. You usually get angina because not enough blood is reaching your heart. The pain you have with angina is similar to the pain of a heart attack. If your angina seems to be getting worse, it may be a warning sign that you're going to have a heart attack.
Like a heart attack, angina usually happens when the vessels that supply blood to your heart (your coronary arteries) get narrower because of a condition known as atherosclerosis (which is also called hardening of the arteries). The main differences between angina and a heart attack are: 
Angina often comes on during exercise and goes away when you rest
Angina usually goes away if you take medicine, such as nitroglycerin
The pain of angina is usually not as bad as the pain of a heart attack, and it doesn't last as long. Angina goes away in about 10 minutes.
A severe attack of angina can feel a lot like a heart attack. If you have any doubts about what is causing your pain, get medical help immediately. Indigestion and acid reflux
Indigestion is any discomfort you feel after eating. Acid reflux happens when acid from your stomach flows back into your throat or into the tube (oesophagus) leading from your throat to your stomach. Indigestion causes pain in the middle of your chest. But the burning pain of indigestion is usually not as bad as the crushing or restricting pain of a heart attack. The pain of indigestion does not usually spread down your arms or into your jaw.Chest infections
Chest infections can cause pain. But it's usually much sharper than the pain of a heart attack. You're more likely to have pain on one side of your chest, not in the middle. If you have an infection, breathing in or coughing makes the pain worse. And the pain usually doesn't spread to your arms or jaw. If you're having a heart attack, breathing in and coughing usually won't make the pain worse.
It can be hard to tell the difference between the pain of a heart attack and something less serious. Studies have found that you're probably not having a heart attack if the pain: 
You probably are having a heart attack if the pain: