From the Guidelines
No, a suppressed thyroid (hypothyroidism) is less likely to cause palpitations compared to hyperthyroidism. When considering the relationship between thyroid function and palpitations, it's essential to distinguish between hyperthyroidism and hypothyroidism. Hyperthyroidism, characterized by an overproduction of thyroid hormones, is well-documented to cause palpitations due to its effects on the cardiovascular system, as noted in a scientific statement from the American Heart Association 1.
Key Points to Consider
- Hyperthyroidism increases the body's metabolic rate, directly affecting the heart and leading to symptoms like palpitations.
- The treatment for hyperthyroidism-related palpitations often includes beta-blockers to lower the heart rate to nearly normal, as recommended in the 2016 Circulation journal 1.
- Hypothyroidism, on the other hand, might occasionally lead to palpitations, but this is less common and typically associated with specific conditions such as anemia or excessive thyroid replacement medication.
- It's crucial to test thyroid function with blood tests measuring TSH, free T4, and possibly free T3 levels if palpitations are experienced, to determine the appropriate course of treatment.
Clinical Implications
Given the information from the American Heart Association 1, the primary concern with palpitations is hyperthyroidism rather than hypothyroidism. Therefore, the focus should be on ruling out hyperthyroidism when palpitations are present, and treatment should be guided by the underlying cause of the symptoms.
From the Research
Thyroid Function and Palpitations
- A suppressed thyroid is typically associated with hypothyroidism, which is characterized by low levels of thyroid hormones in the body 2.
- However, the provided studies primarily focus on hyperthyroidism, which is characterized by high levels of thyroid hormones in the body 3, 4, 5.
- Hyperthyroidism can cause cardiac arrhythmias, heart failure, and other cardiovascular issues, including palpitations 3, 4.
- Subclinical hyperthyroidism, which is defined as low concentrations of thyrotropin and normal concentrations of T3 and FT4, may also cause symptoms such as palpitations 2.
Relationship Between Thyroid Function and Palpitations
- The studies suggest that hyperthyroidism, rather than a suppressed thyroid, is more likely to cause palpitations due to the excessive production of thyroid hormones 3, 4, 5.
- However, subclinical hyperthyroidism, which can be caused by a suppressed thyroid-stimulating hormone (TSH) level, may also lead to palpitations and other cardiovascular symptoms 2.
- It is essential to note that the relationship between thyroid function and palpitations is complex and may depend on various factors, including the underlying cause of the thyroid disorder and the individual's overall health status.
Treatment Options for Thyroid-Related Palpitations
- Treatment options for hyperthyroidism, including antithyroid medications, radioactive iodine ablation, and surgery, may help alleviate palpitations and other cardiovascular symptoms 3, 4, 5.
- In cases of subclinical hyperthyroidism, treatment may be recommended for patients at high risk of osteoporosis and cardiovascular disease, such as those older than 65 years or with persistent serum TSH levels less than 0.1 mIU/L 3.