Palpitations — the sensation of a racing, fluttering, or irregular heartbeat — are often caused by correctable hormonal, nutritional, or metabolic imbalances detectable through blood testing.
Palpitations describe the uncomfortable awareness of your own heartbeat — often felt as a racing, pounding, skipping, or fluttering sensation in the chest, throat, or neck. While they can feel alarming, palpitations are a very common complaint and are frequently caused by physiological imbalances rather than primary heart disease. Understanding the underlying driver is the critical first step toward effective management.
Many causes of palpitations are entirely correctable once identified. Thyroid overactivity is among the most common — excess thyroid hormone accelerates the heart’s electrical conduction system, causing a persistently elevated heart rate and ectopic beats. Iron deficiency and anaemia reduce the blood’s oxygen-carrying capacity, forcing the heart to beat faster and harder to compensate. Electrolyte imbalances — particularly low magnesium or calcium — destabilise the electrical gradient across cardiac muscle cells, triggering irregular rhythms. Elevated cortisol from chronic stress or adrenal dysfunction can also drive sympathetic overdrive, increasing both heart rate and the frequency of ectopic beats.
Palpitations can also be an early signal of poorly controlled blood glucose. Hypoglycaemia triggers an adrenaline surge that directly stimulates the heart, while long-standing insulin resistance and raised HbA1c are independently associated with atrial arrhythmias. A structured blood test panel allows clinicians — and health-conscious individuals — to systematically rule out or identify these correctable causes before assuming a structural cardiac problem.
Most palpitations are benign and caused by correctable factors such as thyroid overactivity, anaemia, or low electrolytes — blood tests can identify these within days. However, palpitations accompanied by dizziness, fainting, chest pain, or a sustained irregular pulse require immediate medical assessment, as these features may indicate a clinically significant arrhythmia.
Palpitations rarely occur in isolation — they are frequently accompanied by other symptoms that help point towards an underlying cause.
Palpitations arise when any factor destabilises cardiac rate, rhythm, or the electrophysiological environment of the heart muscle.
These key blood markers help identify the most common correctable causes of palpitations.
Several underlying conditions can drive palpitations by disrupting the hormonal, metabolic, or electrophysiological environment of the heart.
A systematic approach to investigating palpitations focuses first on the most common correctable blood-based causes before considering cardiac investigations.
TSH and free T4 should be the first blood tests ordered in anyone with unexplained palpitations, as hyperthyroidism is one of the most common and most treatable causes. A suppressed TSH with elevated free T4 confirms thyroid overactivity.
Ferritin, full blood count, and haemoglobin identify iron deficiency and anaemia — two conditions that force the heart to work harder and are fully correctable with supplementation or dietary change.
Serum magnesium, calcium, and HbA1c assess the electrophysiological environment of the heart. Low magnesium in particular is a highly correctable and commonly overlooked trigger for cardiac ectopy.
Cortisol and high-sensitivity CRP evaluate adrenal and inflammatory contributions to sympathetic overdrive. If these are raised alongside palpitations, lifestyle and medical interventions targeting stress physiology are indicated.
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Alongside targeted testing, several evidence-based lifestyle strategies can reduce the frequency and severity of palpitations.
Most palpitations are benign, but certain accompanying features should prompt prompt medical review.
These can point to a more serious underlying cause and should not be ignored.
Yes — iron deficiency and the resulting anaemia are among the most common reversible causes of palpitations. When haemoglobin falls, the heart compensates by increasing its rate and force of contraction to maintain oxygen delivery to tissues. Checking ferritin — the body’s iron storage marker — is a simple, affordable first step to rule this out.
Thyroid disorders are one of the leading correctable causes of palpitations. Hyperthyroidism — including Graves’ disease — causes excess thyroid hormone to overstimulate the heart’s electrical system, resulting in a fast, fluttering, or irregular heartbeat. A TSH blood test is the standard first screening test and should be among the first investigations for anyone with unexplained palpitations.
Several nutritional deficiencies are linked to palpitations. Low magnesium is one of the most significant — magnesium is essential for maintaining the resting electrical potential of cardiac muscle cells, and deficiency predisposes to ectopic beats. Low iron (ferritin) and low calcium also contribute. All three can be measured with a single blood draw.
Yes. Chronically elevated cortisol — from sustained stress, poor sleep, or adrenal dysfunction — maintains the sympathetic nervous system in a state of heightened activation. This raises resting heart rate and increases the frequency of ectopic beats. Cortisol can be measured as part of a blood test panel to assess whether adrenal output is a contributing factor in your palpitations.
Most palpitations are benign, but you should seek urgent medical assessment if palpitations are accompanied by chest pain, fainting, marked breathlessness, or a sustained irregular pulse. If your palpitations occur regularly at rest, wake you from sleep, or are worsening, a blood test panel — covering thyroid function, iron, and electrolytes — is a sensible starting point to identify correctable causes before cardiac imaging is needed.
This page is for general information only and does not replace personalised medical advice. If you are worried about your health, please speak to a qualified healthcare professional. Trupoint Health blood tests are analysed by UK-accredited laboratories.
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