Even mild underactive thyroid if not treated can lead to heart failure

Individuals with a mildly underactive thyroid detectable only with a blood test - are twice as likely to develop heart failure compared to those with normal thyroid levels. Heart failure is when the heart cannot pump enough blood to the body's other organs. The Cardiovascular Health Study included over 3,000 adults over the age of 65 who were followed for over 12 years. Thyroid function was compared to the risk of developing heart failure. Those with a TSH level over 10 had a 200% increased risk of developing heart failure compared to those with normal thyroid levels. The study was performed at the University of California at San Francisco School of Medicine and was presented at the 78th Annual Meeting of the American Thyroid Association on October 4th in New York.