Heart Palpitations? Your Thyroid May Be Overactive

That racing, fluttering feeling in your chest can be frightening, especially when it happens suddenly or repeatedly. While heart palpitations have many possible causes, an overactive thyroid is one of the most common — and most treatable — reasons your heart might be beating irregularly.

Why This Symptom Matters

Your thyroid gland produces hormones that control your metabolism, including how fast your heart beats. When your thyroid becomes overactive (a condition called hyperthyroidism), it floods your body with excess thyroid hormones. This surge acts like pressing the gas pedal on your heart rate.

The result? Your heart may start beating faster than normal, skip beats, or feel like it’s fluttering or pounding in your chest. These sensations can happen even when you’re resting or doing light activities. You might notice your pulse feels rapid or irregular when you check it.

Unlike heart palpitations from anxiety or caffeine, thyroid-related heart issues often persist throughout the day. They may gradually worsen over weeks or months as thyroid hormone levels continue to climb. The good news is that treating an overactive thyroid typically resolves these heart symptoms completely.

Many people with hyperthyroid heart palpitations also experience other symptoms like unexplained weight loss, feeling hot all the time, or having trouble sleeping. Your hands might shake slightly, and you may feel restless or anxious even without obvious stressors.

Could It Be Your Thyroid?

Heart palpitations aren’t always thyroid-related. Common causes include anxiety, caffeine, certain medications, dehydration, or heart conditions. However, thyroid testing makes sense when palpitations occur alongside other hyperthyroid symptoms or risk factors.

You’re more likely to have thyroid-related heart issues if you’re a woman, have a family history of thyroid disease, or are between ages 20-40. Stress, pregnancy, or iodine exposure can sometimes trigger hyperthyroidism in susceptible people. Even if you’ve had normal thyroid tests in the past, thyroid function can change over time.

The key difference with thyroid heart palpitations is they often feel constant or frequent, rather than occasional episodes. If your heart feels like it’s racing even during quiet moments, or if simple activities like walking upstairs leave you breathless, thyroid testing is worth considering.

What Tests Should You Consider?

A comprehensive thyroid panel can reveal if an overactive thyroid is causing your heart palpitations. The most important tests include TSH (thyroid stimulating hormone), which drops when your thyroid is overactive, and Free T4 and Free T3, which measure your actual thyroid hormone levels.

If these basic tests suggest hyperthyroidism, thyroid antibody tests like TSI or TRAb can help identify the specific cause. These antibodies often drive Graves’ disease, the most common form of hyperthyroidism that frequently causes heart symptoms.

What to Expect from Testing

Thyroid testing is straightforward — just a simple blood draw that takes minutes. Most testing services let you order online without a prescription, then visit a nearby lab when convenient. You don’t need to fast or do any special preparation for thyroid tests.

Results typically arrive within 1-3 days via secure online portal. The lab report will show your levels alongside normal ranges, making it easy to spot potential issues. If results suggest hyperthyroidism, you can take them directly to your doctor for treatment discussion.

When to See a Doctor

Seek immediate medical attention if you experience chest pain, severe shortness of breath, fainting, or extremely rapid heart rate (over 120 beats per minute at rest). These symptoms could indicate a serious heart condition requiring urgent care.

For persistent but less severe palpitations, schedule a doctor visit within a week or two. Even if thyroid tests come back normal, your physician can evaluate other potential causes and recommend appropriate heart monitoring if needed.

This content is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.