Palpitations, the sensation of a fast, pounding, or fluttering heart, are a common and often alarming experience. This feeling, which can include a racing heart known as tachycardia or the noticeable thud of a skipped beat, happens when you become acutely aware of your heart’s rhythm. While many episodes are brief and harmless, they can also signal an underlying condition that requires medical evaluation. Understanding the source of these sensations, whether from external inputs, whole-body disorders, or primary heart issues, is the first step toward managing them.
Lifestyle and Emotional Triggers
The most frequent causes of a fast and hard heartbeat stem from daily habits and emotional states, not heart disease. These triggers activate the body’s natural “fight-or-flight” response, which is governed by the sympathetic nervous system. When stress, anxiety, or a panic attack occurs, the body releases catecholamines like adrenaline and norepinephrine. These hormones immediately increase the firing rate of the heart’s natural pacemaker, the sinoatrial node, resulting in a sudden, noticeable increase in heart rate and force.
Stimulants such as caffeine and nicotine directly impact the heart’s electrical system, mimicking the effect of stress hormones. Caffeine increases the rate of depolarization in the sinoatrial node, causing the heart to beat faster. Nicotine stimulates the sympathetic nervous system activity that sends impulses directly to the heart, which raises both heart rate and blood pressure.
Alcohol consumption, particularly binge drinking, can trigger an irregular rhythm often called “holiday heart syndrome,” presenting as atrial fibrillation. Alcohol creates electrical instability by affecting the heart muscle cells and the autonomic nervous system. Dehydration and intense physical exercise also cause palpitations because they decrease blood volume, forcing the heart to pump faster and harder to maintain adequate circulation throughout the body.
Systemic Medical Conditions
The heart can react to conditions originating elsewhere in the body, causing palpitations as a secondary symptom. Hyperthyroidism, where the thyroid gland produces excessive amounts of thyroid hormone, is a recognized cause. These hormones act like powerful stimulants on the heart, increasing the resting heart rate and the force of each contraction.
Anemia, characterized by a reduced amount of oxygen-carrying red blood cells, causes the heart to compensate for the tissue oxygen deficit. To maintain oxygen delivery, the heart must increase its output by beating faster. Similarly, a fever or systemic infection raises the body’s metabolic demand, prompting the heart rate to increase to circulate more blood and immune cells.
Palpitations can also be an unintended side effect of medications prescribed for non-cardiac issues. Common culprits include decongestants containing pseudoephedrine and certain asthma inhalers like albuterol, both of which are stimulants. These compounds activate the adrenergic receptors on the heart muscle, leading to an increased heart rate.
Primary Cardiac Causes
When palpitations are caused by a problem within the heart itself, they are categorized as arrhythmias, which are electrical disturbances that alter the heart’s normal rhythm. Atrial fibrillation (AFib) is a common example, where the upper chambers (atria) beat chaotically and irregularly, sometimes reaching 175 beats per minute. This disorganized electrical activity floods the lower chambers (ventricles) with signals, resulting in a rapid, irregular pounding sensation.
Another frequent cause is Supraventricular Tachycardia (SVT), a fast, regular heart rhythm that originates above the ventricles. SVT is often caused by an electrical short circuit or an extra pathway that allows the heart’s electrical impulse to rapidly cycle, accelerating the heart rate to between 150 and 250 beats per minute. Patients experience this as a sudden onset and cessation of a very fast, uniformly regular heartbeat.
Structural issues, such as heart valve disease or heart failure, can also provoke palpitations. A malfunctioning heart valve may allow blood to leak backward, decreasing forward flow and increasing the heart’s workload. This strain can enlarge the heart chambers and create conditions conducive to irregular electrical activity and a forceful heartbeat. Palpitations from an underlying cardiac disorder may be more likely to occur during physical activity.
Knowing When to Seek Medical Attention
While many palpitations are harmless, certain accompanying symptoms serve as urgent warnings that require immediate medical attention. Seek emergency care if a fast or hard heartbeat is accompanied by chest pain, significant shortness of breath, or lightheadedness. Fainting or losing consciousness with a palpitation is also a serious sign, indicating the heart rhythm is severely compromising blood flow to the brain.
For persistent or frequently recurring palpitations without these severe symptoms, a scheduled visit to a healthcare provider is warranted. Diagnosis often begins with an electrocardiogram (ECG) to capture the heart’s electrical activity. Further evaluation might involve wearing a portable heart monitor, such as a Holter monitor, for 24 hours or longer to record the heart rhythm during typical daily activities. Keeping a detailed log of when the palpitations occur, how long they last, and potential triggers is an important first step in determining the underlying cause.