A heart attack, or myocardial infarction, is a serious medical emergency that occurs when blood flow to a section of the heart muscle is blocked, often by a blood clot. Recognizing the warning signs quickly is paramount to survival and minimizing long-term damage to the heart. While chest pain is the most commonly known symptom, discomfort often radiates to other parts of the body, including the arm. Understanding signs like arm numbness can help ensure a person receives immediate medical attention.
Which Arm is Typically Affected
The sensation of numbness, tingling, or pain most commonly affects the left arm during a heart attack. This discomfort often begins in the chest and then spreads down the arm, sometimes extending all the way to the hand. The sensation can manifest as a deep ache, a feeling of fullness, or a subtle tingling that is easily mistaken for a strained muscle.
While the left arm is the more recognized location, pain or numbness can also occur in the right arm, or in both arms simultaneously. Focusing only on the left side can lead to dangerous delays if symptoms appear on the right side. Any new or unexplained discomfort in either arm, especially when accompanied by other symptoms, should be treated with immediate concern. These sensations are a form of referred pain, where the brain misinterprets the origin of the distress signal.
Understanding Referred Pain
Referred pain is discomfort felt in a location distant from the actual source of the problem. During a heart attack, the brain mistakenly attributes the pain originating from the heart muscle to a different area, such as the arm or jaw. This phenomenon lies in how the sensory nerves from different parts of the body connect to the spinal cord.
The nerves that carry pain signals from the heart converge on the same spinal cord segments that receive sensory input from the arm and shoulder. Because the brain is more accustomed to receiving signals from the somatic nervous system, such as nerves in the arm, it interprets the distress signal coming from the heart as originating from the more familiar location. This neural confusion explains why a heart experiencing a lack of oxygenated blood can present as numbness or tingling in the arm.
Other Heart Attack Symptoms
Arm numbness or pain rarely occurs in isolation, so be aware of other accompanying symptoms that signal a heart attack. The most common sign is uncomfortable pressure, squeezing, fullness, or pain in the center or left side of the chest that lasts for more than a few minutes or goes away and returns. This chest discomfort is often described as feeling heavy or crushing.
Pain or discomfort can also radiate to the jaw, neck, back, or stomach. Beyond pain, a person may experience shortness of breath, which can happen with or without chest discomfort. Other common signs include feeling weak, light-headed, or dizzy, and breaking out in a cold sweat. Nausea or vomiting can also occur, and these symptoms are sometimes dismissed as indigestion.
Symptoms can vary significantly between individuals. While chest pain remains the most common symptom for both sexes, women are more likely to experience less specific signs like unusual or unexplained fatigue, often for days before the event. Women also report nausea, vomiting, and pain in the upper back or jaw more frequently than men. Being aware of these variations is essential for timely recognition and response.
What to Do During an Emergency
If you or someone else experiences symptoms that suggest a heart attack, immediate action is necessary to increase the chance of survival. The first step is to call 911 or the local emergency number immediately. Do not attempt to drive yourself to the hospital, as emergency medical services (EMS) personnel can begin life-saving treatment en route.
While waiting for the ambulance, the person should sit down and try to remain calm. If advised by the emergency operator, and if no contraindications exist, chew and swallow one regular-strength aspirin tablet (typically 325 mg). Aspirin helps prevent blood clotting and can reduce damage to the heart muscle. If the person has been prescribed nitroglycerin, they should take it as directed while awaiting help.