Palpitations, rapid heartbeat and chest discomfort

Palpitations, a rapid heartbeat and chest discomfort may occur when a person becomes unusually aware of the heart beating. The heartbeat may feel fast, forceful, irregular, fluttering, pounding, or as if it skips, pauses, or adds an extra beat. Some people mainly feel the sensation in the chest, while others notice it in the throat or neck.

Chest discomfort may occur at the same time and can feel like pressure, tightness, heaviness, burning, aching, or an undefined awareness in the chest. Palpitations may last only a few seconds or continue for several minutes or longer. They can appear at rest, during exercise, after eating, when lying down, or during periods of stress.

Many episodes are related to temporary factors such as physical activity, anxiety, lack of sleep, dehydration, caffeine, alcohol, nicotine, fever, or medication. Recurrent symptoms may also be associated with an abnormal heart rhythm, anemia, thyroid disease, electrolyte changes, pregnancy, heart disease, or another medical condition.

The sensation alone cannot determine whether the heart rhythm is normal or abnormal. The timing, pulse rate, duration, triggers, associated symptoms, medical history, and an electrocardiogram help guide the diagnostic pathway.

How palpitations and a rapid heartbeat may feel

Palpitations can have different patterns. Some episodes begin and stop suddenly, while others develop gradually. A person may feel only one isolated skipped beat or a continuous rapid rhythm.

Common descriptions include:

• a pounding or forceful heartbeat
• rapid beating or racing in the chest
• fluttering or trembling sensations
• a skipped beat followed by a stronger beat
• an irregular or uneven pulse
• brief pauses between heartbeats
• pulsation felt in the throat or neck
• chest pressure, tightness, aching, or burning
• lightheadedness, weakness, or breathlessness during an episode
• difficulty exercising at the usual level

Some people notice palpitations more clearly when lying quietly because there are fewer distractions. A normal heartbeat may also feel stronger after exercise, emotional stress, a large meal, caffeine, or a sudden fright.

Common causes of palpitations, rapid heartbeat and chest discomfort

Physical activity, stress, and strong emotions

The heart normally beats faster during exercise, fear, excitement, pain, fever, or emotional stress. Adrenaline increases heart rate and the force of contraction. This can make the heartbeat more noticeable even when the rhythm itself is normal.

Anxiety and panic episodes can cause a rapid heartbeat, chest tightness, trembling, sweating, tingling, dizziness, and rapid breathing. These symptoms can resemble a heart problem. A new or unexplained episode should not automatically be attributed to anxiety before relevant medical causes are considered.

Caffeine, alcohol, nicotine, and other stimulants

Coffee, energy drinks, nicotine, alcohol, recreational substances, some weight-loss products, and certain cold or decongestant medicines may trigger palpitations or increase the heart rate.

The effect depends on the dose, individual sensitivity, hydration, sleep, other medication, and underlying heart health. Symptoms may become more noticeable when several triggers occur together, such as poor sleep, dehydration, stress, and high caffeine intake.

Premature beats and other rhythm disturbances

An early heartbeat arising from the upper or lower chambers of the heart may feel like a skipped beat, pause, or sudden thump. Occasional premature beats are common, but frequent or symptomatic episodes may require heart rhythm monitoring.

Other arrhythmias can cause the heart to beat too fast, too slowly, or irregularly. Possible examples include supraventricular tachycardia, atrial fibrillation, atrial flutter, and rhythm disturbances arising from the lower chambers of the heart.

An arrhythmia is more concerning when palpitations occur with fainting, near-fainting, significant breathlessness, chest pain, known heart disease, or a family history of sudden cardiac death.

Fever, dehydration, and illness

Fever, infection, vomiting, diarrhea, heat exposure, and inadequate fluid intake can increase heart rate. Dehydration may also lower blood pressure and cause dizziness, weakness, or a sensation of the heart racing when standing.

A rapid pulse during illness may reflect the body’s response to fever, pain, low fluid volume, reduced oxygen, inflammation, or another physiological stress.

Anemia and blood loss

Anemia reduces the blood’s oxygen-carrying capacity. The heart may compensate by beating faster or more forcefully. Associated symptoms can include fatigue, pale skin, dizziness, headaches, breathlessness during activity, and reduced exercise tolerance.

Possible contributors include iron deficiency, heavy menstrual bleeding, gastrointestinal bleeding, nutritional deficiency, chronic disease, or another blood disorder. Laboratory testing is needed to determine whether anemia is present and why.

Thyroid, glucose, and electrolyte changes

An overactive thyroid can cause a rapid or irregular heartbeat, sweating, heat intolerance, weight loss, tremor, anxiety, and difficulty sleeping. Other thyroid conditions and thyroid medication doses can also affect heart rate.

Low blood glucose may cause palpitations together with sweating, shaking, hunger, weakness, or confusion. Electrolytes such as potassium, magnesium, sodium, and calcium support normal electrical activity in the heart, and significant disturbances may affect rhythm.

Medication and supplements

Palpitations may occur with certain asthma inhalers, thyroid medicines, stimulants, antidepressants, decongestants, attention-related medication, herbal products, and other treatments.

Medication should not be stopped abruptly without professional advice. A doctor may review the dose, timing, interactions, and whether symptoms began after a new medicine or a change in treatment.

Pregnancy and hormonal changes

Pregnancy increases blood volume and cardiac workload, so some people become more aware of their heartbeat. Hormonal changes during menstruation, perimenopause, and menopause may also coincide with palpitations.

Symptoms during pregnancy still require assessment when they are persistent, severe, associated with fainting, chest pain, breathlessness, marked weakness, or another concerning symptom.

Structural and other heart conditions

Heart valve disease, heart muscle disease, coronary artery disease, inflammation of the heart, congenital heart conditions, and heart failure may cause palpitations, chest discomfort, fatigue, breathlessness, swelling, or reduced exercise tolerance.

Chest discomfort may also arise from muscles, ribs, reflux, the lungs, or anxiety. Because different conditions can feel similar, the cause should not be determined from the location or quality of discomfort alone.

Symptoms that may occur together

Associated symptoms help determine how urgently the palpitations should be assessed. Important symptoms include:

• chest pain, pressure, tightness, heaviness, or burning
• shortness of breath or difficulty taking a full breath
• dizziness, lightheadedness, or near-fainting
• fainting or loss of consciousness
• unusual fatigue or sudden weakness
• sweating, nausea, or pale, blue, or gray skin
• a very fast, very slow, or clearly irregular pulse
• reduced exercise tolerance
• ankle swelling or breathlessness when lying down
• fever, weight loss, tremor, or heat intolerance
• heavy bleeding, black stool, or other signs of blood loss

When emergency medical care is needed

Seek emergency medical care if palpitations or a rapid heartbeat are currently occurring with:

• chest pain, pressure, heaviness, or severe tightness
• significant shortness of breath
• fainting, collapse, or severe lightheadedness
• new confusion or marked weakness
• pain spreading to the arm, shoulder, back, neck, or jaw
• cold sweating, nausea, or rapid deterioration
• a very fast or irregular heartbeat that does not settle
• sudden neurological symptoms such as weakness, facial drooping, or speech difficulty

These symptoms may indicate an acute heart rhythm problem, heart attack, circulation problem, or another urgent condition. The person should not drive themselves if they feel faint, severely unwell, or have significant chest symptoms.

When to arrange a medical assessment

A medical assessment is recommended when palpitations:

• keep returning or are becoming more frequent
• last longer than a few minutes
• begin and stop suddenly
• occur during exercise or wake the person from sleep
• are associated with dizziness, chest discomfort, or breathlessness
• appear after starting or changing medication
• occur during pregnancy
• are associated with anemia, thyroid, or glucose-related symptoms
• occur in a person with known heart disease
• are accompanied by a family history of serious rhythm disorders or sudden cardiac death

How palpitations and rapid heartbeat are usually diagnosed

Medical history, pulse, and clinical examination

The assessment usually begins with the exact sensation, duration, frequency, and circumstances of each episode. The doctor may ask whether the symptoms begin gradually or suddenly, whether the pulse feels regular, and whether they occur after exercise, meals, caffeine, alcohol, medication, stress, or standing.

The examination may include pulse rate and rhythm, blood pressure, oxygen saturation, heart and lung sounds, thyroid findings, signs of anemia, swelling, and symptoms of infection or dehydration.

Electrocardiogram and heart rhythm monitoring

An electrocardiogram records the electrical activity of the heart. It may identify an arrhythmia when symptoms are present during the test, but a normal result between episodes does not exclude an intermittent rhythm problem.

A Holter monitor records continuously for one or more days. Longer event monitors or wearable rhythm devices may be considered when symptoms occur less frequently. The aim is to match the recorded rhythm with the time of the reported symptoms.

Laboratory testing

Depending on the clinical picture, blood tests may include:

• complete blood count and iron status
• thyroid function
• electrolytes, including potassium and magnesium
• blood glucose
• kidney function
• inflammatory or infection-related tests
• pregnancy testing when relevant

Laboratory testing can identify contributing conditions but does not replace rhythm recording when an arrhythmia is suspected.

Heart ultrasound and additional tests

An echocardiogram may be recommended when a structural heart problem, valve disease, heart muscle condition, or heart failure is suspected. An exercise test may be relevant when symptoms occur during activity.

Further testing depends on the history, examination, electrocardiogram, and whether symptoms suggest a rhythm disorder, coronary disease, lung condition, or another cause.

What the next step may involve

The next step depends on whether the recorded rhythm is normal, prematurely triggered, persistently fast, irregular, or associated with another medical condition. Occasional symptoms related to identifiable temporary triggers may require monitoring and review of caffeine, alcohol, nicotine, hydration, sleep, and medication.

Recurrent episodes may require an electrocardiogram, Holter monitoring, laboratory testing, or cardiology assessment. Symptoms during exercise, fainting, or known heart disease generally require a more direct cardiovascular pathway.

If anemia, thyroid disease, infection, electrolyte disturbance, medication effects, or another contributing condition is identified, treatment is directed toward that cause. A confirmed arrhythmia may require monitoring, medication, a procedure, or another individualized cardiology plan.

Checking the pulse and recording the time and duration of an episode can be useful, but repeatedly checking consumer devices may increase anxiety and cannot replace clinical interpretation.

What to prepare before a medical appointment

Before an appointment or ZagrebMed inquiry, prepare information about:

• when the palpitations started and how often they occur
• whether the heartbeat feels fast, forceful, irregular, or skipped
• how long each episode lasts
• whether symptoms begin and stop suddenly or gradually
• the pulse or smartwatch reading during symptoms, if available
• chest discomfort, breathlessness, dizziness, fainting, or weakness
• possible links with exercise, meals, caffeine, alcohol, stress, sleep, or posture
• medicines, inhalers, supplements, stimulants, and recreational substances
• previous heart, thyroid, anemia, glucose, or electrolyte findings
• previous electrocardiograms, Holter monitoring, laboratory tests, or cardiology reports

If palpitations, a rapid heartbeat, or chest discomfort persist or repeatedly return, you can send ZagrebMed a description of the episodes and available medical documentation. ZagrebMed can help connect the symptoms with an electrocardiogram, heart rhythm monitoring, laboratory testing, cardiology consultation, or another appropriate diagnostic pathway in Zagreb.