Not all people having heart attacks experience the same symptoms or even the same degree of symptoms. Some people have none. Symptoms may come and go, however, common signs often indicate that a heart attack is happening, or will occur soon. The more symptoms that happen at once, the more important it is to seek medical help quickly. Immediate medical attention should be sought for any new or unusual symptom as many heart attack patients have very mild symptoms. If heart attack symptoms are present, do not wait--call 911 right away. Fast action saves lives. Common symptoms include: