The Link Between Thyroid Disorders and Heart Conditions

Maybe your heart pounds quickly and loudly, you feel dizzy, it's hard to catch your breath. Or maybe you feel your heart skipping beats, racing, or pounding.

You may not realize that what feels like a panic attack or heart palpitations can be symptoms of hyperthyroidism—the overproduction of thyroid hormones by the thyroid gland, a butterfly-shaped organ at the base of the neck. These symptoms can occur because your thyroid and heart function are closely linked.

This article looks at the connection between the two. It discusses possible causes of these symptoms and the thyroid levels that may lead to them. It also explains what treatment options can help

The Heart-Thyroid Link

What affects your thyroid can affect your heart, and vice versa.

This means that if you suspect or are diagnosed with thyroid disease, you should also be checked for heart disease.

Likewise, you may have a heart disease such as atrial fibrillation, heart failure, or a slow heart rate called bradycardia. This means you should have your thyroid function checked.

That's because having a thyroid disorder increases your chances of developing heart disease. Studies show that thyroid hormone treatment for people with an underactive thyroid helps to reduce this risk. It remains less clear how such hormone therapy might benefit those who have a history of chronic heart failure or a heart attack.

Thyroid and Heart Symptoms

Your thyroid function impacts how your heart works. This is true whether it is underactive, as in hypothyroidism, or is overactive in what is known as hyperthyroidism. It's also why the thyroid can be the cause of some of the symptoms discussed here.

Hyperthyroidism and Your Heart

Some people may be misdiagnosed as having panic disorder or heart problems. In reality, they may actually have an overactive thyroid. The body makes too much thyroid hormone, which causes the heart to work harder. This can create symptoms such as:

• Rapid heart rate, even at rest and especially after exertion
• Higher blood pressure
• Heart palpitations
• Increased cardiac output (the amount of blood the heart pumps through the body)
• Increased pulmonary artery pressure (this vessel moves blood from the heart to the lungs)
• Chest pain
• Increased heart contractions

Once treated for their overactive thyroid, these people go on to be free of these symptoms. However, the condition also raises the risk for other heart conditions.

These other issues can lead to palpitations and feelings akin to panic attacks on their own. They include:

• Heart failure
• Atrial fibrillation (an irregular heartbeat)
• Pulmonary hypertension (high blood pressure in your heart and lungs)
• Angina (chest pain due to heart disease)

A condition called toxic multinodular goiter, caused by nodules growing on the thyroid gland, also may cause episodes of overactive thyroid. These episodes can be a trigger for panic attacks or cause heart palpitations.

Hypothyroidism and Your Heart

One type of underactive thyroid condition is called Hashimoto’s disease. It can sometimes cause unpredictable releases of excess thyroid hormone. This also may lead to heart symptoms, but not in all people. That's because hypothyroidism actually creates less of a demand on your heart.

When heart signs and symptoms do occur, they may include:

• Slower heart rate (bradycardia)
• Lower systolic blood pressure
• Higher diastolic blood pressure
• Lower cardiac output (the amount of blood the heart pumps through the body)
• Fewer heart contractions
• Shortness of breath after exertion
• Pericardial effusions (excess fluid around the heart)
• Edema (swelling) of the hands and feet

Another condition is very common in people with an underactive thyroid. It is called dyslipidemia and means that the lipids (fats) in your blood are abnormal. This condition raises your risk of heart disease, including the chance of a heart attack.

Treatment

Usually, most people who have thyroid conditions find that once they're properly treated, the symptoms go away. These treatments may include medications, radioactive iodine, or surgery for people with overactive thyroids. They also include hormone replacement therapy in people with hypothyroidism.

Healthcare providers who are treating thyroid disorders will sometimes give other drugs too. Often, they may prescribe a type of blood pressure medication called a beta blocker. These drugs include Inderal (propranolol) and Tenormin (atenolol). They may be given to people with hyperthyroidism to ease symptoms like a fast heart rate and palpitations.

Other Potential Causes

If you've been treated for your thyroid and you're still having heart or panic attack-like symptoms, you'll need to see your healthcare provider. They will help you to sort out if thyroid disease is really what's causing these episodes or if something else is at work. There are several other possibilities that may be involved.

Mitral Valve Prolapse

This is an irregularity in a heart valve that normally allows blood to move between between two chambers of your heart. It is more common in thyroid patients.

People with a mitral valve prolapse may see symptoms such as:

• A fast, pounding heartbeat
• Heart palpitations
• Panic attacks
• Dizziness
• Shortness of breath
• Fatigue
• Chest pain

This condition can be diagnosed by an echocardiogram, or medical imaging of the heart. There also are treatments, including the beta blocker drugs, that can alleviate your symptoms.

TSH Level

Another issue to talk about with your healthcare provider is your level of thyroid-stimulating hormone (TSH). This can be treated with radioactive iodine (RAI), antithyroid drugs, or surgery for hyperthyroidism. Many people have an underactive thyroid after treatment, so they are placed on hormone replacement therapy.

But if your thyroid hormone replacement dosage is too high, and your TSH is at the lower end of the normal range, you may be borderline hyperthyroid. This is due to overmedication. In this case, it's worth discussing a therapy adjustment with your provider to see if it helps with your symptoms.

In the same way, if you're having periods of hyperthyroidism due to Hashimoto’s disease or toxic nodules, improved treatment may help resolve your panic and heart symptoms.

Mental Health Disorder or Heart Problem

If you and your healthcare provider cannot find a thyroid-related reason for your symptoms, you may, in fact, have a panic or anxiety disorder. You may also have some type of heart condition. In these cases, you should be further evaluated by a heart specialist and/or a psychiatrist.

Besides heart problems or an anxiety disorder, other causes of panic attacks include:

• Drug use (stimulants such as caffeine, cocaine, or amphetamines)
• Hypoglycemia (low blood sugar)
• Medication withdrawal
• Adrenal gland issues, including pheochromocytoma

Summary

Symptoms that may feel like they are owed to a panic attack or a heart condition may be just that. But in some cases, they may be due to an overactive or underactive thyroid.

When that's the case, many people find that their symptoms go away once their thyroid condition is treated.

You'll need to get to the bottom of what's causing your symptoms, so talk to your healthcare provider to be checked for these other potential causes if necessary.