A heart attack, medically known as a myocardial infarction, occurs when blood flow to a section of the heart muscle is severely reduced or blocked, causing tissue damage. While many people associate heart attacks with sudden, crushing chest pain, symptoms can often be more subtle and include a phenomenon called referred pain. Referred pain means that the discomfort is felt in a location other than the heart itself, frequently manifesting as pain in the shoulder or arm. Understanding the specific location of this pain is important for recognizing a potentially life-threatening event.
The Specific Answer: Referred Pain Location
Pain from a heart attack most commonly manifests as discomfort or an ache that spreads to the left side of the body, particularly the left shoulder and down the left arm. This classic presentation is often described as a heavy, squeezing, or aching sensation that does not subside with rest or position change. The pain may extend all the way down to the elbow or even the fingers. However, heart attack pain is not exclusively limited to the left side. Pain can also be felt in the right shoulder, both shoulders simultaneously, or the upper back. Atypical presentations can involve pain felt only in the neck, jaw, or back, without significant chest or shoulder discomfort. The presence of sudden pain in either shoulder warrants immediate medical attention.
The Mechanism of Referred Pain
The sensation of pain in the shoulder, arm, or jaw during a heart attack is due to a neurological process called referred pain. This phenomenon occurs because the sensory nerves from the heart and the sensory nerves from the shoulder and arm share common pathways into the spinal cord. The pain signals originating from the oxygen-deprived heart muscle travel through these shared spinal nerve segments, primarily in the thoracic region. The brain is not accustomed to receiving pain signals from the heart, so it struggles to accurately pinpoint the source of the discomfort. Instead, it misinterprets the signal as coming from a more familiar location that shares the same nerve pathway, such as the shoulder or arm. This shared wiring causes the resulting shoulder pain to be a miscommunication within the nervous system.
Other Critical Heart Attack Symptoms
While shoulder discomfort is a notable sign, a heart attack rarely presents with this symptom alone. The most common symptom remains chest pain or discomfort, typically felt as pressure, fullness, or a squeezing sensation in the center of the chest. This discomfort can last for several minutes or disappear and then return.
Other common accompanying symptoms include shortness of breath, unexplained cold sweats, sudden lightheadedness or dizziness, and nausea or vomiting. These symptoms are sometimes mistakenly attributed to indigestion or a flu-like illness, leading to dangerous delays in seeking treatment.
It is important to note that women and individuals with diabetes often present with atypical symptoms. Women are more likely to experience unusual fatigue, back pain, or jaw and neck pain without the classic chest pain. Diabetics may have a “silent heart attack” with only mild discomfort or pressure, due to nerve damage (neuropathy), which can mask typical pain signals. Recognizing these subtle presentations is vital, as they can lead to delays in diagnosis and treatment.
Immediate Action and When to Seek Help
Any new or unusual shoulder pain, especially when combined with other symptoms like chest pressure, shortness of breath, or cold sweats, must be treated as a medical emergency. The most important action is to immediately call 911 or your local emergency number. Do not attempt to drive yourself or the person experiencing symptoms to the hospital, as emergency medical services (EMS) personnel can begin life-saving treatment on the way. While waiting for help, the person should rest in a comfortable position, typically sitting down with knees bent to ease strain on the heart. If the person is conscious and not allergic, and if advised by emergency services, they may chew and swallow a standard aspirin tablet, which helps prevent blood clotting.