The ONE organ responsible for high blood pressure.
What to Know About Hyperthyroidism and High Blood Pressure
Hyperthyroidism increases systolic blood pressure by decreasing systemic vascular resistance, increasing heart rate, and raising cardiac output.
When the thyroid gland doesn't produce enough thyroid hormone (hypothyroidism) or produces too much thyroid hormone (hyperthyroidism), high blood pressure can result.
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.
What is hyperthyroidism?Hyperthyroidism is a condition that causes a person’s thyroid gland to produce too much 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.
Over the past few decades, researchers 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
- heart failure
- 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.
SymptomsThe symptoms of hyperthyroidism reflect the overactive metabolism that the disease causes. Therefore, common symptoms 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
- feel nervous
- have tremors
- feel short of breath
- get tired easily
- experience muscle weakness
Risk factorsBeing a biological female and being over 60 years old increase a person’s risk of hyperthyroidism. A person is also more likely to have hyperthyroidism if they have a pre-existing health condition such as pernicious anemia, type 2 diabetes, or primary adrenal insufficiency. Other risk factors include:
- having a family history of thyroid disease
- eating a diet rich in iodine, such as kelp
- taking medication that contain iodine
- using nicotine, such as smoking or vaping
- being pregnant within the previous 6 months
Treatment optionsDoctors 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.
Thyroid medicationsDoctors may prescribe medications such as beta-blockers to treat the effects of hyperthyroidism. Beta-blockers work mainly in the heart to prevent substances, such as adrenaline, from affecting nerve cells. This treatment reduces blood pressure and heart rate, which can help to reduce palpitations and anxiety. However, beta-blockers do not affect on thyroid hormone production. Antithyroid medication reduces thyroid hormone production and may temporarily reduce Graves’ disease symptoms. This is an autoimmune condition causing hyperthyroidism. Doctors most commonly prescribe methimazole, but if a person is pregnant, they may recommend propylthiouracil. In rare cases, methimazole may harm the fetus. Some people experience side effects from taking antithyroid medicines, including:
- an adverse reaction, such as a rash and itching
- a reduction in white blood cells, which can lower immune defenses and reduce resistance to infection
- in rare cases, liver failure
Radioiodine therapyRadioiodine therapy slowly kills off the cells that produce thyroid hormone. It does not affect other tissues in the body. People take this treatment orally in capsule or liquid form. Doctors do not prescribe radioiodine therapy during pregnancy as it can harm the fetus. A person is extremely likely to develop hypothyroidism following radioiodine therapy. However, doctors consider hypothyroidism easier to treat than hyperthyroidism. Therefore, they may decide this is the right choice for some individuals.
Thyroid surgeryIf a person has a goiter — a swollen neck due to enlargement of the thyroid gland — doctors may recommend surgery. They may also suggest it for a person with hyperthyroidism during pregnancy when other treatments are potentially harmful or inadequate. Depending on the individual and how much of the thyroid gland surgeons remove, a person may develop hypothyroidism and require medications to treat this condition.
When to contact a doctorIt is important for a doctor to check a person’s thyroid function if they are experiencing any of the previously mentioned symptoms, including palpitations, diarrhea, and excessive sweating. If a person experiences any of the following symptoms after taking thyroid medication, they should contact their doctor immediately:
- tiredness or weakness
- dull pain in the abdomen
- loss of appetite
- skin rash, itching, or easy bruising
- yellowing of the skin or whites of the eyes
- a constant sore throat
- fever or chills