How the Thyroid Affects the Heart in Women

Thyroid Conditions and How They Can Affect the Heart

Hypothyroidism (Underactive Thyroid)

Hypothyroidism happens when the thyroid does not produce enough hormone. This can slow down many systems in the body, including the heart. Over time, women may notice a slower heart rate, rising cholesterol levels, stiffer blood vessels, fatigue or weight gain.

Low thyroid hormone levels can also raise LDL (“bad”) cholesterol and contribute to the buildup of plaque in blood vessels, which may increase the long-term risk of cardiovascular disease.

Together, these changes help explain the link between hypothyroidism and heart disease, especially when low thyroid levels go untreated.

Hyperthyroidism (Overactive Thyroid)

Hyperthyroidism occurs when the thyroid produces too much hormone. This can cause the heart to work harder than it should. Women may notice a faster or irregular heartbeat, heart palpitations, shortness of breath, higher blood pressure or a fluttering feeling in the chest.

These changes help explain the link between hyperthyroidism and heart problems, and why regular monitoring plays an important role in care.

Cardiovascular Risks for Women

Women are more likely than men to develop thyroid disorders, and that difference matters for heart health. When thyroid hormone levels run low or high, it can change the way the heart works and how blood moves through the body. Over time, these changes can raise blood pressure and affect cholesterol — both risks for heart disease.

Research shows that thyroid hormone imbalance can influence heart function in ways that matter for lifelong cardiovascular health. The American Heart Association notes that a healthy thyroid is an important part of overall heart health.

Because thyroid conditions are more common in women — including autoimmune forms such as Hashimoto’s and Graves’ disease — paying attention to symptoms and screening is especially important. When thyroid levels stay out of balance, risks such as high blood pressure, irregular heart rhythms and changes in cholesterol can develop quietly over time.

Routine blood tests and early treatment give clinicians the best chance to protect both thyroid function and heart health.

Prevention and Treatment of Thyroid Imbalance

The good news is that most thyroid conditions are very treatable. Once a thyroid imbalance is diagnosed, treatment can often help restore hormone levels and reduce strain on the heart. For an underactive thyroid, this usually means taking a daily medication that replaces missing hormones. For an overactive thyroid, treatment may include medication to slow hormone production or other therapies based on a woman’s specific needs.

Protecting both thyroid and heart health also means paying attention to everyday habits. Regular physical activity, balanced nutrition, stress management and routine checkups all play a role. Simple blood tests can catch thyroid changes early — often before heart symptoms begin.

Thyroid Symptoms in Women

It is easy to brush off small changes when life feels busy. But noticing what feels different in your body can help you catch health issues early. Talk with a physician if you notice:

• Anxiety or low mood
• Changes in menstrual cycles
• Hair thinning
• Heart palpitations
• Sensitivity to cold or heat
• Sudden weight changes
• Unusual fatigue

These can sometimes point to thyroid imbalance.

“Most thyroid conditions are highly manageable once they are properly diagnosed,” said Dr. Hossain. “Early evaluation and appropriate treatment can help restore hormone balance, improve symptoms, and reduce the risk of long-term complications. If a person notices persistent changes in their health, a simple blood test can often help determine whether the thyroid may be involved.”