Quick answer
Hypothyroidism can potentially cause heart palpitations in some cases. However, the connection is complex and not fully understood. Some possible ways hypothyroidism may contribute to palpitations include effects on heart rate, blood pressure, heart function, and adrenal gland function. Treatment of the thyroid condition may help resolve palpitations.
What are heart palpitations?
Heart palpitations are the sensation that your heart is pounding, fluttering, or beating too hard or too fast. It may feel like your heart is skipping a beat. Palpitations are caused by changes in your heart rate or rhythm. Some common causes include:
- Exercise
- Stress or anxiety
- Caffeine, alcohol, nicotine
- Dehydration
- Electrolyte imbalances
- Anemia
- Pregnancy
- Menopause
- Medications
- Heart conditions like arrhythmias
Palpitations are generally harmless but can sometimes indicate an underlying heart issue. It’s important to discuss recurring palpitations with your doctor.
What is hypothyroidism?
Hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormone. The thyroid helps regulate growth, metabolism, and other vital body functions.
Common causes of hypothyroidism include:
- Hashimoto’s disease – autoimmune disorder that damages the thyroid
- Thyroiditis – inflammation of the thyroid
- Radiation treatment of the thyroid
- Surgical removal of part or all of the thyroid
- Certain medications
- Iodine deficiency
- Pituitary gland disorders
Symptoms of hypothyroidism may include:
- Fatigue
- Weight gain
- Constipation
- Dry skin and hair
- Intolerance to cold
- Joint pain
- Depression
- Impaired memory
Hypothyroidism is typically diagnosed through blood tests and treated by replacing the missing thyroid hormones. Levothyroxine is the standard medication used.
Can hypothyroidism cause palpitations?
There does appear to be a potential link between hypothyroidism and heart palpitations in some people. A few ways hypothyroidism could contribute to palpitations include:
Effects on heart rate
Thyroid hormones help control the heart’s rhythm and rate. Low thyroid levels may cause the heart to beat more slowly at rest. However, in some cases they may also contribute to a racing heart rate. Fluctuations in heart rate can trigger palpitations.
Effects on blood pressure
Thyroid disorders are associated with higher diastolic blood pressure (the bottom number of a blood pressure reading). High blood pressure can stimulate the heart to beat harder, which you may notice as palpitations.
Direct effects on the heart
Thyroid hormones act directly on heart muscle cells and blood vessels. Thyroid deficiency could potentially impair heart function. This may lead to cardiac arrhythmias and other issues that produce palpitations.
Adrenal effects
The thyroid gland and adrenal glands are closely linked. Chronic thyroid problems may cause mild adrenal insufficiency. Adrenal hormones help regulate heart rate and rhythm. Low adrenal function could trigger heart palpitations.
Anxiety and stress
Hypothyroidism can cause symptoms like brain fog, fatigue, and depression. These effects may indirectly increase anxiety and worsen palpitations. Stress hormones like adrenaline can stimulate a rapid heartbeat.
Studies on hypothyroidism and palpitations
Several studies have explored the relationship between hypothyroidism and palpitations:
- A 2019 study found that 13% of hypothyroid patients reported palpitations as an initial symptom. Levothyroxine treatment resolved palpitations in most of these cases.
- A 2015 study of over 900 hypothyroid patients found that nearly 11% experienced palpitations. They were more common in women and patients with more severe hypothyroidism.
- A 2014 study reported that 37% of hypothyroid patients had cardiac arrhythmias like atrial fibrillation. Thyroid treatment reduced the incidence.
- A 1990 study found that hypothyroid patients showed significantly higher adrenaline levels compared to healthy controls, indicating increased stimulation of the adrenal glands.
Overall the evidence suggests thyroid deficiency may potentially disrupt normal heart rhythms in some people. However more research is still needed on the mechanisms involved.
Other heart-related effects of hypothyroidism
In addition to palpitations, untreated hypothyroidism can have other cardiac effects including:
- High cholesterol – Thyroid hormones help regulate cholesterol levels. Low thyroid function may raise total and LDL cholesterol.
- Atherosclerosis – High cholesterol levels accelerate the buildup of fatty plaques in arteries, increasing heart disease risk.
- Heart failure – Thyroid deficiency causes the heart to pump less efficiently. Over time heart failure may develop.
- Enlargement of the heart – The heart may enlarge in an effort to compensate for weaker pumping action.
Managing hypothyroidism helps lower cardiovascular risk and prevent complications.
Other causes of palpitations
While hypothyroidism may trigger palpitations in some cases, it’s important to note heart rhythm issues can have many other causes including:
- Caffeine, alcohol, tobacco
- Strenuous exercise
- Dehydration
- Electrolyte imbalance
- Anemia
- Pregnancy
- Menopause
- Medications like albuterol or asthma inhalers
- Heart conditions like atrial fibrillation or mitral valve prolapse
- Panic attacks
- Chronic stress
- Sleep apnea
Your doctor can help determine whether your palpitations may be due to hypothyroidism or other factors. Discuss any new, recurring, or concerning symptoms and request appropriate testing.
When to see a doctor
Occasional, brief palpitations are usually not serious. However, consult your doctor if you experience:
- Frequent or prolonged palpitations
- Racing heartbeat episodes
- Palpitations along with dizziness, lightheadedness or fainting
- New palpitations after age 50
- Palpitations triggered by exertion
Prompt medical evaluation is recommended if palpitations are interfering with your quality of life. Call 911 or emergency services immediately for palpitations with chest pain, difficulty breathing, loss of consciousness, or other concerning symptoms.
Diagnosing causes of palpitations
To determine the cause of palpitations, your doctor may recommend:
- Medical history – Discussion of your symptoms, family history, medications, and any existing conditions.
- Physical exam – Listening to your heart rhythm, assessing thyroid, checking reflexes.
- Electrocardiogram (ECG) – Records the electrical activity of your heart to detect abnormalities.
- Event monitor – Wearable ECG monitor to record your heart rhythm over a period of time.
- Echocardiogram – Ultrasound imaging of the heart structure and function.
- Blood tests – Check thyroid hormone levels, electrolytes, blood counts, and cardiac enzymes.
Further testing like a stress test, Holter monitor, or electrophysiology study may be warranted in some cases. Your doctor will determine which evaluations are appropriate based on your medical history and symptoms.
Treating hypothyroidism to resolve palpitations
If low thyroid function appears responsible for your palpitations, thyroid hormone replacement medication is the primary treatment approach.
Levothyroxine is the standard synthetic thyroid hormone drug used to treat hypothyroidism. The starting dose is typically 25-50 mcg daily, which is gradually increased until thyroid lab tests are normalized.
Relieving the thyroid deficiency with levothyroxine can often eliminate heart rhythm issues originating from the condition. Close monitoring and medication adjustments are done to determine the optimal dosage that resolves symptoms.
Improvements in palpitations may lag behind other hypothyroid symptoms like fatigue. It can take months for the heart and other body systems to fully stabilize after thyroid levels are optimized.
Managing palpitations from hypothyroidism
Other strategies to help manage palpitations associated with hypothyroidism include:
- Avoiding triggers like caffeine, alcohol, tobacco, stress, dehydration
- Staying well hydrated by drinking sufficient water
- Practicing relaxation techniques like meditation, yoga, deep breathing
- Following an electrolyte-balanced diet
- Taking magnesium or potassium supplements if deficient
- Exercising regularly within your limits
- Establishing good sleep habits
- Using strategies to manage anxiety or depression
- Avoiding certain medications that may exacerbate palpitations
Conventional anti-arrhythmic medications or procedures are rarely needed for managing palpitations associated with hypothyroidism. But they may be options if symptoms are severe and persist after thyroid function is stabilized.
Preventing hypothyroidism and complications
For those without existing thyroid disease, steps to help prevent hypothyroidism include:
- Eating a balanced diet with adequate iodine
- Avoiding very high or low iodine intake
- Managing other autoimmune conditions that increase risk
- Using thyroid shields for needed dental or medical imaging procedures
- Promptly treating viral infections that may trigger thyroiditis
- Keeping other risk factors like cholesterol and blood pressure under control
Thyroid testing is recommended for high-risk groups like women over 60, those with family history of thyroid disease, and people with symptoms of hypothyroidism. Early detection and treatment helps prevent complications.
Conclusion
Hypothyroidism has the potential to cause heart palpitations and arrhythmias in some cases. The mechanisms likely involve effects on heart rate, blood pressure, direct heart cell function, and adrenal gland activity. However, palpitations often have multiple possible causes.
Anyone experiencing new, recurring, or concerning palpitations should see a doctor for an evaluation. Diagnostic testing can help determine whether there is an underlying thyroid or cardiac issue that requires treatment.
For palpitations caused by hypothyroidism, thyroid hormone replacement is typically effective at resolving symptoms when dosed appropriately. Ongoing medical monitoring and self-care steps like stress reduction, proper hydration, and electrolyte balance are also important for managing palpitations. Controlling thyroid function can alleviate troubling symptoms and improve patients’ heart health and quality of life.