Thyroid Isthmus

The thyroid gland is a butterfly-shaped organ in your neck.  The thyroid gland plays a crucial role in regulating your body’s metabolism.  The part of the thyroid gland that connects the right and left lobes is called the isthmus.  In this article, we will discuss what the thyroid isthmus is.

What Is the Thyroid Isthmus?

The thyroid isthmus is a thin strip of tissue that connects the two lobes of the thyroid gland. Think of it as a bridge that unites the “wings” of the butterfly.

Thyroid Isthmus Location

Located just below your Adam’s apple, the thyroid isthmus can sometimes be seen and felt when you swallow. It’s positioned right in the middle, forming a link between the right and left thyroid lobes.

Function of the Thyroid Isthmus

The isthmus connects the right and left thyroid lobes.

Thyroid Gland Overview

The thyroid gland which includes the isthmus consists of two lobes on either side of the trachea.  The thyroid is responsible for producing hormones that regulate various bodily functions, such as metabolism, temperature control, and energy production.

Thyroid Hormone Production

The thyroid gland produces two main hormones: thyroxine (T4) and triiodothyronine (T3). These hormones play a pivotal role in regulating the body’s metabolism, ensuring that the cells get the right amount of energy to function

Thyroid Imaging Techniques

Thyroid issues are common, and accurate imaging is crucial for diagnosing and treating thyroid conditions. Several imaging techniques are used, and the isthmus is imaged in these procedures.

  1. Ultrasound: Ultrasound imaging is a commonly used technique to examine the thyroid. It provides a clear view of the thyroid isthmus and helps identify any abnormalities or growths within the gland.
  2. CT Scans: Computed Tomography (CT) scans are valuable for visualizing the thyroid gland, including the isthmus. They offer detailed cross-sectional images that aid in diagnosis.
  3. MRI: Magnetic Resonance Imaging (MRI) can be used to obtain high-resolution images of the thyroid gland, revealing the isthmus’s structure and any potential issues.
  4. Thyroid Scintigraphy: This nuclear medicine technique involves injecting a small amount of radioactive material to observe how the thyroid functions. It can help diagnose conditions like hyperthyroidism and goiter.

Common Thyroid Isthmus Conditions

Thyroid conditions can affect the isthmus, leading to various health concerns. Some of the issues that may involve the isthmus include:

  • Thyroid Nodules: Abnormal growths in the thyroid that may require evaluation and treatment.
  • Thyroiditis: Inflammation of the thyroid gland that can affect the isthmus as well.
  • Goiter: Enlargement of the thyroid, which can sometimes extend into the isthmus area.


The thyroid isthmus connects the right and left lobes of the thyroid. Imaging procedures like ultrasound will image the thyroid of which the isthmus is a part.   Conditions like nodules and inflammation can involve the entire thyroid to include the isthmus.

Disclaimer: The content of this website is provided for general informational purposes only and is not intended as, nor should it be considered a substitute for, professional medical advice. Do not use the information on this website for diagnosing or treating any medical or health condition. If you have or suspect you have a medical problem, promptly contact your professional healthcare provider.

Similar Posts