Hypothyroidism vs. Hyperthyroidism – What’s the Difference (Part 1)

Today, Dr. Raymond Douglas sits down with thyroid surgeon Dr. Babak Larian of the CENTER for Advanced Head & Neck Surgery and Chief of the Department of Otolaryngology at Cedars-Sinai. Patients often ask us about the differences between hypothyroidism vs. hyperthyroidism, so Dr. Douglas asks Dr. Larian to explain each condition.

Hypothyroidism vs. Hyperthyroidism

What is Hyperthyroidism?

Hyperthyroidism occurs when the thyroid gland produces too much thyroid hormone.

What is Hypothyroidism?

Hypothyroidism occurs when the thyroid gland produces too little thyroid hormone.

What does the Thyroid Hormone do?

Our bodies have a very fine control over thyroid hormone production. The brain has a gland that produces Thyroid Stimulating Hormone (TSH), and the TSH goes to the thyroid gland, which then produces T4 (thyroid hormone). T4 gets transformed into T3, the activated form of the thyroid hormone. This is what ultimately causes the body to adjust the metabolism of every single cell in the body.

In people with a normal thyroid, the TSH levels, free T3 levels and free T4 levels are all within a normal range, meaning the amount of hormone your thyroid is producing is appropriate. The T4 and TSH have an inverse relationship, so when the T4 numbers go up, the TSH goes down and vice versa.

In hyperthyroid patients, we see elevated free T3 and/or T4 levels and low TSH. This means the thyroid is malfunctioning and producing too much hormone, so the TSH level will be low.

On the other hand, in hypothyroid patients, we see low free T3 and/or T4 and an elevated TSH. This means the thyroid isn’t producing enough thyroid hormone, so the TSH level will be elevated.

For people with a normal functioning thyroid in the normal range, we see fine-tuning in the balance of these levels, but when the numbers get out of range in either direction, that indicates either hypothyroid or hyperthyroid state.

Now that you have an understanding of hypothyroidism vs. hyperthyroidism, be sure to check back in next week as Dr. Larian and Dr. Douglas discuss how hyperthyroidism and hypothyroidism affect Graves’ disease.

Learn about Thyroid Treatment Options from Dr. Larian

For more Thyroid Thursday episodes, please visit Dr. Douglas’ YouTube channel!

Posted in: Thyroid Eye Disease

Call Our Office Today

(310) 657-4302

Send Us a Message

  • This field is for validation purposes and should be left unchanged.