Hyperthyroidism increases systolic blood pressure by decreasing systemic vascular resistance, increasing heart rate, and raising cardiac output.

Is hyperthyroidism related to hypertension?

When the thyroid gland doesn't produce enough thyroid hormone (hypothyroidism) or produces too much thyroid hormone (hyperthyroidism), high blood pressure can result.

How does thyroid disease cause hypertension?

Hypothyroidism can weaken the heart muscle and heart rate, reducing the heart's pumping capacity and increase the stiffening of blood-vessel walls. The combination of these changes can lead to hypertension.