Hyperthyroidism causes the body to produce too much thyroid hormone. People with this condition are more likely to have cardiovascular conditions such as high blood pressure, known as hypertension.

The thyroid gland plays an important role in how the body uses energy. If it overproduces thyroid hormone, it can speed up bodily functions, such as the heart rate. As a result, this can cause increased blood pressure.

According to the American Thyroid Association (ATA), people are also at increased risk of coronary artery disease, stroke, heart failure, and atrial fibrillation — an irregular heart rhythm.

What is hyperthyroidism?

Hyperthyroidism is a condition that causes a person’s thyroid gland to produce too muchTrusted Source thyroid hormone.

The thyroid is a small, butterfly-shaped gland that sits at the front of the neck. It is sometimes called overactive thyroid. This condition is the opposite of hypothyroidism — an underactive thyroid.

Thyroid hormones control energy metabolism, which is the way the body uses energy. This means they affect almost every organ, including the heart.

Thyroid disorders and blood pressure

Over the past few decades, researchersTrusted Source have explored the effects of hypothalamus-pituitary-thyroid (HPT) axis genetic mutations on the cardiovascular system. The HPT axis is responsible for maintaining the usual circulating levels of thyroid hormone.

The ATA reports that people with hyperthyroidism are at increased risk of a range of cardiovascular conditions, including:

• hypertension, or high blood pressure

• atrial fibrillation
• coronary artery disease
• stroke
• heart failure

Additionally, a 2020 studyTrusted Source found that hyperthyroidism can increase:

• Cardiac output: The amount of blood the heart pumps each minute.
• Systolic blood pressure: The force generated by the heart pumping blood around the body.
• Renin, angiotensin, and aldosterone levels: These are essential substances for regulating blood volume and the force on the blood vessels of the circulating blood.

If a person’s hypertension is due to hyperthyroidism, treating the thyroid condition can resolve both issues.

Symptoms

The symptoms of hyperthyroidism reflect the overactive metabolism that the disease causes. Therefore, common symptomsTrusted Source of hyperthyroidism include:

• unintentional weight loss despite maintaining the same dietary intake
• palpitations — a fast, fluttering, or pounding heartbeat
• diarrhea or an increase in bowel movements
• intolerance to heat
• excessive sweating
• menstrual irregularities

A person may also:

• feel nervous
• have tremors
• feel short of breath
• get tired easily
• experience muscle weakness

Treatment options

Doctors treat a person’s hyperthyroidism according to the underlying cause and severity of the condition. Different treatment options work for different people — there is no one-size-fits-all approach. However, the aim of any treatment is to bring thyroid hormones back down to typical levels.

The three main treatment types for hyperthyroidism include medication, radioiodine therapy, and thyroid surgery.