Hyperthyroidism and heart palpitations

Palpitations may feel like fluttering, pounding, racing or skipped beats in the chest. Hyperthyroidism commonly presents with palpitations, and the sensation may occur alongside tremor, excessive sweating, heat intolerance, feeling anxious, difficulty sleeping or unexplained weight loss. These symptoms can also have other causes, so the sensation alone cannot identify a thyroid problem.

An overactive thyroid releases too much thyroid hormone. This can increase the heart's sensitivity to adrenaline and make the pulse faster or more forceful. In some people, the rhythm becomes irregular. A clinician may check your pulse, blood pressure and neck, then arrange blood tests for thyroid hormones. An electrocardiogram can help assess the heart rhythm when symptoms are persistent, troublesome or irregular.

Arrange a medical assessment if palpitations are new, recurring or accompanied by other symptoms of an overactive thyroid. Record when they start, how long they last, whether the rhythm feels regular, and what you were doing at the time. Mention medicines, supplements, decongestants, caffeine, nicotine and recreational drugs, because some can affect heart rate.

If hyperthyroidism has already been diagnosed, take treatment exactly as prescribed and keep follow-up appointments so hormone levels and symptoms can be reviewed. Do not change or stop thyroid medicine without advice. Until you are assessed, rest during an episode and avoid personal triggers such as stimulant drinks if they make the sensation worse.

Seek emergency help if palpitations do not settle or occur with chest pain, severe shortness of breath, fainting, new confusion, marked weakness or severe dizziness. An unusually fast or irregular heartbeat with a high fever, agitation or worsening illness also needs urgent assessment, particularly if hyperthyroidism is known.

For symptoms that stop but keep returning, contact a clinician promptly. Bring a list of medicines and a description of the episodes. Urgent assessment is based on the symptoms and how you feel, not on whether palpitations are a common feature of thyroid disease.

Ask whether your symptoms warrant thyroid blood tests and an electrocardiogram, whether a medicine could be contributing, and which warning signs should prompt emergency care. If hyperthyroidism is confirmed, ask how treatment is expected to affect your pulse and when your thyroid levels should be checked again.