Thyroid System Overview: It’s Symptoms & Levels

The thyroid is a small gland located in the neck that primarily regulates metabolism and other important functions through the production and release of several key hormones. Unfortunately, diseases involving the thyroid are all too common, affecting nearly 20 million Americans. Because these diseases often cause a hormone imbalance, they can lead to a variety of negative outcomes throughout the body. In this article, we will guide you towards the overview of the thyroid system.

thyroid system
Overview of the thyroid system

Thyroid System Overview or T4 levels

T4, or Thyroxine or Thyroid System, is one of the primary hormones produced by the thyroid gland. T4 levels or Thyroid system play a critical role in many bodily functions, including metabolism, temperature control, and weight gain. A common method of diagnosing thyroid disease is by measuring T4 levels in the blood and comparing them to a healthy reference range.

Thyroid Stimulating Hormone

Thyroid Stimulating Hormone, or TSH, is a hormone produced in a different gland found in the brain, called the Pituitary Gland. When blood levels of thyroid hormones are too low, the Pituitary Gland releases Thyroid Stimulating Hormone, causing the thyroid gland to release more of its hormones.

What is considered a dangerously high TSH level?

Most Endocrinologists do not agree on what is considered a dangerously high TSH level, though 0.4 – 4 mU/L is generally considered the typical TSH reference range. In generally, a TSH rest result measuring >4 mU/L is indicative of hypothyroidism.

Treatment of Thyroid

The treatment of thyroid diseases varies depending on the specific condition. The most common types of thyroid diseases are hypothyroidism and hyperthyroidism, which indicate an under and over active thyroid, respectively.  For each condition, there are multiple methods to the treatment of thyroid diseases, includes traditional medications to a more natural approach.

Thyroid Medication

The use of FDA approved thyroid medication is the most common and well documented treatment approach. Thyroid medication for the treatment of hypothyroidism include drugs includes levothyroxine  and nature thyroid, where hyperthyroidism drugs include methimazole and propylthiouracil.

Thyroid medication side effects

Thyroid medication side effects are not uncommon, though many are not serious in nature. With levothyroxine, perhaps the most widely used thyroid medication, patients may experience side effects such as weight loss, diarrhea, sweating, and difficulty sleeping. More serious thyroid medication side effects may include decreased bone mineral density, cardiovascular complications, and difficulty breathing, though these are less frequently seen.


Hypothyroidism is the most common condition involving the thyroid gland and is characterized by an underactive thyroid. Before treatment, patients suffering from hypothyroidism may experience symptoms such as fatigue, weight gain, increased sensitivity to cold, and constipation. In addition to a physical exam, hypothyroidism is typically diagnosed from blood tests measuring the amount of various thyroid hormones present in the blood.

Hypothyroidism Causes

Hyperthyroidism causes can originate from a number of sources. Iodine deficiency, though no longer frequent in developed countries, may play a role. Thyroid surgery, autoimmune conditions, and even certain medications are other potential hypothyroidism causes.

Hypothyroidism Diet

There is no medically accepted hypothyroidism diet, though several minerals have proved to be important in managing this condition. The most well documented of these is iodine, an essential mineral used by the thyroid gland to make thyroid hormones. Selenium and zinc, found in food such as chicken, tuna, and eggs, may also be incorporated into the hypothyroidism diet.  

Hyperthyroidism Symptoms

Because this condition is characterized by an over production in thyroid hormones, hyperthyroidism symptoms commonly include weight loss, rapid heartbeat, and increased appetite. Other hyperthyroidism symptoms that patients may experience are sweating, nervousness, and increased sensitivity to heat.

Symptoms of Hyperthyroidism

Symptoms of hyperthyroidism are caused by an overproduction in thyroid hormones T3 and T4, which play a role in the regulation of many functions in the body such as weight, metabolism, temperature control, sleep, and energy. As such, symptoms of hyperthyroidism may include weight loss, increased metabolism, sensitivity to heat, difficulty sleeping, and fatigue.

Hyperthyroidism Treatments

Hyperthyroidism treatments can range from traditional medications, includes methimazole and propylthiouracil, to surgical therapy, and even radioactive iodine. Because hyperthyroidism is caused by an overproduction of thyroid hormones, surgically removing part of the thyroid gland is an effecting hyperthyroidism treatment option. Radioactive iodine, a less invasive treatment approach, is taken by mouth and is absorbed by the thyroid gland, causing it to shrink. Both of these hyperthyroidism treatments may result in lower-than-ideal thyroid hormone, requiring correction with medications such as levothyroxine.

Hyperthyroidism Medication

Most hyperthyroidism medications are focused on reversing the cause of the problem which is overproduction of thyroid hormones.  These drugs are known as anti-thyroid medications and include drugs includes methimazole and propylthiouracil. Other hyperthyroid medication is aimed at symptom control with beta blockers being the prime example. Beta blockers, while typically used to lower blood pressure, can also be used to slow a rapid heartbeat which is a common symptom of hyperthyroidism.

Graves Disease Symptoms

Graves Disease autoimmune condition, is another way in which patients may acquire hyperthyroidism. In Graves Disease, the body produces antibodies that target the thyroid gland, causing it to produce excess thyroid hormones. Graves Disease symptoms are like hyperthyroidism symptoms, which include weight loss, difficulty sleeping, and tremor. Other Graves Disease symptoms are bulging eyes, goiter development, and anxiety. To aid the thyroid gland using a natural dietary supplement, please check our products page by clicking on either of the following links: USA Visitors or International Visitors.


TSH (thyroid stimulating hormone) test. Medline Plus. Accessed March 31, 2020.

Thyroid disease. Cleaveland Clinic. Accessed March 31, 2020.

How doctors diagnose hypothyroidism. Endocrine Web. Accessed March 31, 2020.

Thyroxine (T4) test or Thyroid System. Medline Plus. Accessed March 31, 2020.

Levothyroxine. Micromedex. Accessed March 31, 2020. 

Hypothyroidism. The Mayo Clinic. Accessed March 31, 2020.

Hypothyroidism diet. Healthline. Accessed March 31, 2020.

Hyperthyroidism. The Mayo Clinic. Accesed March 31, 2020.