The first alarming symptom of the atrial fibrillation (AFib) is often described as heart palpitations. People report sensations of fluttering, pounding, or a rapid, skipping beat. The rhythm can feel irregular and episodic, as if the heart is surging ahead unpredictably. These perceptions may appear at rest or during activity and can vary in duration and intensity from one episode to the next.
Not a typical heartbeat is a common description for atrial fibrillation. Periods of faster rhythm may alternate with quieter intervals, making a steady pattern hard to identify. Many individuals note daily awareness of an uneven beat, including pounding or trembling sensations in the chest. The underlying irregular electrical activity of the atria can produce an uneven ventricular response and a variable pulse.
Overall fragility and an ongoing feeling of being tired. General fatigue may be present, with a sense that the body’s energy has declined. Weakness can be diffuse or more noticeable in specific areas. For example, after attending a soccer game, an individual might note heaviness in the legs, particularly around the knees. In some people, AFib is reported alongside these reductions in perceived stamina.
A breakneck symptom can refer to light-headedness that recurs during the day. Fluctuating blood pressure and an irregular rhythm are frequently discussed in relation to these episodes. Whether pressure trends higher or lower, dizziness can occur, sometimes accompanied by unsteadiness. The duration varies, with brief spells in some people and longer periods in others.
Never stopping tediousness is another reported feature. With physical effort, individuals may feel overwhelmed sooner than expected, even during routine tasks. Extra sleep does not always relieve this sense of exhaustion. In accounts of AFib, an erratic heartbeat may coincide with lower exercise capacity and quicker onset of tiredness.
Inability to take a deep breath. Shortness of breath can resemble what is experienced in asthma or other conditions. It is often noted after activities such as swimming, running, or cycling, and may occasionally appear at rest. In AFib, irregular filling and pumping efficiency can be discussed as possible contributors to these breathing sensations.
Poor physical activity performance. Exercise intolerance is commonly mentioned, with fatigue emerging within minutes of more intensive training. Day-to-day activities, such as shopping or walking longer distances, may feel unusually demanding. This pattern reflects a reduced ability to sustain effort when rhythm is irregular.
Episodes of increased perspiration can occur at times that do not match ambient temperature or exertion. Some people report sweating more frequently than peers, with episodes arising even in mild conditions. In descriptive reports, this pattern is sometimes associated with atrial fibrillation and fluctuations in heart rhythm.
When having an atrial fibrillation, a person may experience light to heavy headedness. If the brain receives less oxygenated blood during rapid, irregular rates, spinning sensations, imbalance, or brief loss of awareness can occur. Fainting is described in some accounts. These episodes are often linked to abrupt rhythm changes and uneven circulation.
Enteric discomfort. Early on, some individuals note a mild abdominal ache that can intensify over time. Digestive symptoms arise for many reasons, but in the presence of other features listed above, they are occasionally reported alongside AFib. The pattern can range from intermittent, dull sensations to sharper discomfort.
Learn more about atrial fibrillation at American Heart Association (AHA).