Can Anaemia or Thyroid Problems Cause Palpitations? 

When an individual experiences heart palpitations, the focus is naturally on the heart itself. However, the heart often acts as a ‘messenger’ for other systems in the body. Two of the most common non-cardiac causes of heart flutters and a racing pulse are anaemia and thyroid disorders. Both conditions alter the body’s internal chemistry or oxygen demands, forcing the heart to change its rhythm to compensate. This article explains how these systemic issues can disrupt your heartbeat and why a simple blood test is often the first step in finding a solution. 

What We’ll Discuss in This Article 

• The clinical relationship between oxygen transport (anaemia) and heart rate 

• How thyroid hormones regulate the heart’s electrical ‘pacemaker’ 

• Why low iron levels lead to a pounding or racing heart 

• The impact of an overactive thyroid (hyperthyroidism) on ectopic beats 

• Common symptoms that link these conditions to heart flutters 

• Differentiating between lifestyle triggers and metabolic causes 

• Emergency guidance for severe symptoms 

How Anaemia and Thyroid Disorders Can Trigger Palpitations? 

Yes, both anaemia and thyroid problems are well-recognised clinical causes of heart palpitations. In anaemia, the lack of red blood cells means the heart must beat faster and more forcefully to deliver enough oxygen to the body. With thyroid problems particularly an overactive thyroid the excess hormones act as a direct stimulant to the heart’s electrical system. While these palpitations can feel identical to those caused by stress or caffeine, they are driven by a measurable underlying metabolic or haematological imbalance. 

In the UK, GPs frequently screen for these conditions when a patient presents with new or worsening palpitations. Because the heart is structurally normal in these cases, the rhythm issues typically resolve once the underlying anaemia or thyroid dysfunction is successfully treated. 

How Anaemia Triggers Palpitations 

Anaemia occurs when you do not have enough healthy red blood cells to carry adequate oxygen to your tissues. This creates a state of ‘high output’ demand on the cardiovascular system. 

• Increased Heart Rate: To make up for the ‘thin’ blood, the heart increases its beats per minute (tachycardia) to circulate the available oxygen more rapidly. 

• Bounding Pulse: The heart often contracts more forcefully, which is felt by the patient as a thumping or pounding sensation in the chest and neck. 

• Ectopic Beats: The strain of the increased workload can make the heart’s electrical cells more irritable, leading to skipped or extra beats. 

• Iron Deficiency: Even without full anaemia, low iron stores (ferritin) can sometimes cause palpitations by affecting how heart cells produce energy. 

Thyroid Disorders and Heart Rhythm 

The thyroid gland produces hormones that act as the ‘thermostat’ for the body’s metabolism. Heart cells are extremely sensitive to these hormones, which can speed up or slow down the heart’s internal clock. 

• Hyperthyroidism (Overactive): An excess of thyroid hormone (T3 and T4) makes the heart more sensitive to adrenaline. This frequently causes a racing heart, frequent ectopic beats, and, in some cases, Atrial Fibrillation. 

• Hypothyroidism (Underactive): While less common, an underactive thyroid can cause a very slow heart rate (bradycardia), which may lead to ‘escape’ ectopic beats as the heart tries to maintain a steady rhythm. 

• Metabolic Sensitivity: Thyroid issues change how the heart handles electrolytes like potassium, which are vital for a stable electrical signal. 

Differentiation: Anaemia vs. Thyroid vs. Anxiety 

Because palpitations feel similar across many conditions, doctors look for ‘clustering’ symptoms to help identify the likely cause before blood tests are even performed. 

Feature	Anaemia-Related	Thyroid-Related	Anxiety-Related
Palpitation Type	Pounding, heavy, or racing heart.	Rapid racing or chaotic fluttering.	Sudden racing or isolated thumps.
Physical Sign	Pale skin, brittle nails, or a sore tongue.	Hand tremors, weight loss, or heat intolerance.	Shaking, sweating, or dry mouth.
Energy Levels	Extreme fatigue and breathlessness.	Feeling ‘wired’, restless, or exhausted.	Tense, ‘on edge’, or panicky.
Onset	Gradually worsens with physical activity.	Can happen at rest or during sleep.	Linked to stressful thoughts or events.
Pulse	often fast and strong.	May be fast and very irregular.	Fast but usually regular.

Conclusion 

Anaemia and thyroid problems are primary examples of how the heart responds to the body’s wider needs. Whether it is the heart speeding up to compensate for low oxygen in anaemia or reacting to the stimulatory effects of thyroid hormones, the resulting palpitations are a physiological response to an underlying imbalance. For most patients, identifying these causes through a routine blood test leads to effective treatment and the complete resolution of heart flutters. However, while these causes are often manageable, the presence of associated chest pain or fainting remains a medical priority. 

If you experience severe, sudden, or worsening symptoms, such as crushing chest pain, fainting, or severe breathlessness, call 999 immediately. 

Authority Snapshot 

This article was reviewed by Dr. Stefan Petrov, a UK-trained physician with an MBBS and certifications in Advanced Cardiac Life Support (ACLS) and Basic Life Support (BLS). Dr. Petrov has extensive hands-on experience in general medicine and intensive care units, ensuring this guide provides medically accurate and safe information. This article explores how systemic issues like anaemia and thyroid dysfunction directly influence heart rhythm, the physiological mechanisms involved, and when to seek medical review.