The thyroid gland is a small butterfly-shaped organ located in the lower part of the neck and is often described as the "master controller" of the body. This important organ is responsible for the production of hormones that help to regulate the body's metabolism (read more about what human metabolism is here), energy levels and general well-being. Understanding the structure and function of the thyroid gland can help you appreciate the importance of maintaining a healthy hormone balance. In this article, we will take a detailed look at the thyroid gland and explore its various roles in the body.

 

Structure and function of the thyroid gland

The thyroid gland is made up of two lobes connected by a thin septum. The thyroid gland is controlled by special nerve cells located in the brain: the hypothalamus and the pituitary gland. They control the production of thyroid hormones by signalling the amount of hormones the body needs. The thyroid gland is also made up of a network of blood vessels and lymph vessels that help transport hormones and nutrients to all parts of the body.

 

- The hypothalamus is a small gland in the brain that is responsible for monitoring the body's metabolism and changes in hormone levels. When the metabolism or hormone levels in the body are lower than the required level, the hypothalamus sends a message to the pituitary gland.

 

- The pituitary gland is a small gland located under the hypothalamus and behind the nose. This gland secretes a hormone called thyroid stimulating hormone (TSH). TSH travels in the bloodstream to the thyroid gland, where it stimulates the production of two other hormones that are very similar to each other, tetraiodothyronine (T4), also known as thyroxine, and triiodothyronine (T3). These hormones are derived from the amino acid tyrosine: T3 has three iodine atoms and T4 has four iodine atoms. Both of these hormones travel through the bloodstream to the brain and nervous system, the liver, the digestive tract, the muscles and all other parts of the body to cause changes in metabolism and hormone levels.

 

Symptoms, diagnosis and treatment of thyroid disorders

The thyroid gland can malfunction when it produces too little or too much hormone, i.e. when it is unable to regulate the right and sufficient amount of hormone in the body. Risk factors for thyroid disorders can include: genetics, age, lifestyle, diet and certain medications. The most common thyroid disorders are:

- Hypothyroidism - a condition in which the thyroid gland is underactive and less thyroxine is produced than normal. This can lead to metabolic disorders, reduced energy levels, fatigue, depression and weight gain. 

- Hyperthyroidism is a condition in which the thyroid gland is overactive and thyroxine production is higher than normal. This can lead to increased metabolism, increased energy levels, insomnia and weight loss. 

- Hashimoto's disease is a condition in which the body's immune system attacks and damages the thyroid gland. This can lead to hypothyroidism and inflammation of the thyroid gland. 

 

Nutrition and lifestyle tips to maintain a healthy thyroid

A healthy diet and lifestyle can help maintain a healthy thyroid and prevent thyroid disorders. Maintain a healthy body weight, practise stress management techniques, exercise regularly, drink plenty of water and do not smoke. A healthy diet rich in fruit, vegetables, whole grains, legumes, nuts and seeds can help maintain a healthy thyroid. Avoid iodised salt, goitrogenic foods (cabbage, broccoli, cauliflower, Brussels sprouts, Chinese cabbage (a type of Beijing cabbage), wasabi, sweet potatoes, peppers, peaches), limit caffeine intake, eat foods rich in iodine (seafood, iodised salt, potatoes, avocados, bananas, cantaloupe, seaweed, almonds and raisins), eat plenty of foods rich in iron (legumes, green leafy vegetables, walnuts and almonds), vitamin B2 and vitamin B3 (beans, nuts and whole grains).

 

Thyroid FAQs

- Can exercise affect the thyroid gland? 

Yes, exercise can affect the thyroid gland. Regular exercise can help maintain a healthy thyroid by improving metabolism, which can help burn excess calories and reduce the risk of obesity. 

 

- How can I prevent thyroid disorders?

You can prevent thyroid disorders by following a healthy diet and lifestyle. 

 

- What are the signs and symptoms of a thyroid disorder? 

Symptoms of a thyroid disorder can include fatigue, weight gain or loss, sleep disturbances, mood swings, persistent hot or cold sensations, and changes in hair and skin. 

 

For more articles on hormones, see:

What are hormones? How do they affect the body?;

What is estrogen?;

What is serotonin?;

Melatonin, what is it and how does this hormone work?.