Why does a heart attack cause left arm pain?
A heart attack is a medical emergency involving a blockage to the blood supply of the heart.
The heart is a muscular pump which requires a constant supply of blood (carrying Oxygen). The blood is supplied by small arteries (known as Coronary Arteries). These blood vessels can become blocked resulting in a section of the heart being starved of oxygen and dying – this is a heart attack.
Pain from a heart attack can occur in the chest but also radiating down the left arm. So why does this occur?
The heart is an organ within your body so does not have a well defined sense of pain. In contrast, your fingertips are very sensitive and able to pinpoint exactly where pain occurs – think about a papercut or a burn, in this situation you know exactly where the injury is.
Pain from the heart (known as cardiac pain) can occur in several places such as the left arm, jaw and shoulders.
This is because the sensory fibres carrying information about the heart connect into the same part of the spinal cord as the sensory fibres from the left arm and jaw.
The brain is unable to distinguish between information from the heart and the information coming from the arm. Therefore it perceives the pain as occurring in the arm.
Sometimes the pain can also be felt in the right arm, back or abdomen.
In rare situations, a heart attack may not cause any pain at all. These so called ‘Silent Heart Attacks’ are most common in the elderly and people with diabetes.
It is important if you suspect a heart attack to call for emergency medical help as soon as possible. Remember ‘time is muscle’ when dealing with heart attacks, the sooner the victim receives specialist medical help the more heart muscle can be saved.