5. Pain Under the Arm
While pain in the chest is the most obvious symptom to correlate with a heart attack, it can also occur in other areas as the pain spreads and projects. Pain under the arm and especially on the left side is common and is often mistaken for normal muscular pain.
Essentially, this pain happens because the heart is sending pain signals to the nerves. The pain often comes and goes and feels worse with exercise an other forms of physical exertion.