Normal Thyroid Levels

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What Is the Thyroid?

Located in the neck, this is a fatty gland that is similar in shape to a butterfly. Responsible for regulating serious bodily processes, the thyroid is most well-known for distributing hormones that control the metabolism specifically. The release of these hormones are responsible for regulating a multitude of functions, including:

  • Thyroid Gland DrawingBreathing, which mostly circulates the gland’s proximity in the throat and to the respiratory system.
  • The heart rate, as too many or few hormones control the circulation of the blood and the speed at which the heart pumps the blood.
  • Central nervous system functions, which control both the body and mind with a specific focus on the brain and spinal cord.
  • Peripheral nervous system functions, which transmit signals from the brain to stimulate movement. This places a specific focus on the muscles and joints.
  • Weight, due to the control over the metabolism.
  • Muscle strength, which also circulates the control over the body’s metabolic rate.
  • Temperature due to the secretion of hormones.
  • Cholesterol levels, which stem from the control over the heart rate and the way that the metabolism breaks down certain lipids.
  • Menstrual cycles as a result of the hormone secretions in females.

Part of the endocrine system, the thyroid gland is responsible for producing, storing, and maintaining two, specific hormones: Triiodothyronine (T3) and Thyroxine (T4). A balance of these hormones is essential in maintaining regular and proper body functions as well as in avoiding both physical and mental illnesses.

What are Normal Thyroid Levels?

A typical thyroid test is conducted through the blood, but a vast array of other options are available if a patient should need more in-depth results. According to the 3rd edition of Clinical Methods: The History, Physical and Laboratory Examinations, a thyroid blood test and other forms of testing tend to demonstrate the following results that constitute normality:

  • Serum thyroxine: 5 to 12 nanograms per deciliter.
  • Free thyroxine fraction: 0.03%
  • Free Thyroxine index: 4 to 12 nanograms per deciliter.
  • Serum Triiodothyronine: 80 to 180 nanograms per deciliter.
  • Radioactive iodine uptake: 10% to 30%
  • Thyroxine-binding globulin: 12 to 20 nanograms per deciliter.
  • Serum thyroglobulin l: 0 to 30 nanograms per deciliter

A thyroid function test usually exists in favor of diagnosing problems affiliated with the gland–especially in patients who are demonstrating symptoms that might symbolize that their thyroid is administering too much T3 or T4 hormones, or even too little. Common signs affiliated with thyroid disruptions include:

  • Mood swings, including anxiety.
  • Sweating or consistent chills, due to the inability to adapt to temperature changes.
  • Hair loss
  • Irregular menstruation in women
  • Trembling of the hands
  • Irregular sleeping patterns

Normal thyroid levels that have been determined through a thyroid test will decide if these symptoms result from other conditions or if it is, in fact, an irregularity of the thyroid gland. Of course and as previously mentioned, a thyroid blood test can reveal serious conditions, like hyper or hypothyroidism.

What Is Hypothyroidism and How Is It Treated?

This is a condition that affects over three million people in the United States each year. This disorder results when the gland does not produce enough thyroid hormones, which contributes to a vast plethora of symptoms. While those most commonly affected by this condition are women in their 60s, people of all ages suffer from underactive thyroid, including rare cases of children as young as age two. Women, ages nineteen to forty are likely to suffer from this debilitating condition as well. Though this is treatable by medical professionals, it is not an enjoyable condition to deal with, and those affected by it demonstrate symptoms of a thyroid problem, including:

  • Chronic fatigue, despite receiving a full night’s rest.
  • The constant feeling of being cold (cold sensitivity).
  • Brittle, cracked nails that do not grow well.
  • Hair loss and dry hair.
  • Sexual dysfunction
  • Slow heart rate (bradycardia).
  • Severe mood swings, including bouts of depression and anxiety. Consistent irritability is also a symptom.
  • Noticeable weight gain that is difficult to track and lose, despite eating right and exercising.
  • Uterine bleeding, even in menopausal women.
  • A thyroid that appears enlarged in imaging.
  • Delayed puberty in young adults
  • Constipation
  • A lack of appetite, due to irregular leptin hormone levels.
  • A delay in growth that stems from the delay in puberty in young adults.
  • A lack of attention span and mental function.


Side Effects PillsTypically, treating this condition circulates the process of hormone replacement therapy, in which individuals take medication to replace the lost hormones. The hormone therapy regulates body processes in the manner intended for them, and attempts to generally maintain the activity of the organs. Essentially, the manner that everything works is regulated with this course of action. Taking natural thyroid supplements is another way to counter these conditions.

Levothyroxine is a common prescription drug used to treat hypothyroidism; it is also used to treat enlarged thyroids, thyroiditis, and even certain forms of thyroid cancer. For more information about this treatment, visit our article: Complete Overview of Synthroid and Armour Thyroid. Multiple brand names of this same medication exist, too, including:

  • Unithroid
  • Synthroid
  • Tirosint
  • Levothroid
  • Levoxyl
  • Novothyrox

Routine visits with endocrinologists to check the progress of the condition is essential as well.

Distinguishing Normal from Common Thyroid Conditions

There is no argument against the importance of a properly working thyroid gland. The conditions that ensue from the production of insufficient or excessive T3 and T4 hormones have detrimental effects on human health as a whole, so it is best to undergo routine screenings–especially if any symptoms of an irregular gland are being demonstrated. A surfeit of testing options exist to determine thyroid issues, and it is best to discuss the most effective one for your prospective disorder with your primary care physician or endocrinologist.

  1. Reply
    Dena Hodge February 12, 2019 at 6:13 pm

    I have had hypothyroidism for 30 years. In the last 10 years my test results are puzzling. One test it will at one point the dr will set my meds but when I come back and retest my results have either Gone up or down. So my dr. Readjust My meds again and we repeat the process. And the test will come back way the other directions so we are adjusting again. I need to understand

  2. Reply
    JOANN BEATTY October 4, 2018 at 3:40 pm

    I had my thyroid removed when i was 8 years old.
    I have been taking synthroid medication all me life, since I was 8 years old.
    I just found out all synthroid medication except for 50MG has food coloring in all the pills except 50MM.

    I purchase synthroid medication instead of Levothyroxine (generic) now on Medicare and synthyroid is
    so high price, I was going to change to Levothyroxine.

    I just find out that all Synthyroid medication has food dye and food coloring. except 50 MM

    When i go to doctors I am going to request 50MM and I will take 2 pills at day = 100MG

    That is so wrong to add food coloring to your pill,that COSTS ALOT MORE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

  3. Reply
    ezhil February 23, 2017 at 7:21 am

    I had thyroid problem slightly by taking 25mcg after 2 months when I tested doctor told that my thyroid is normal anyway u shall continue for 6 months but still I have no improvement my sudden weight is not reduced my menstrual cycle is not regular can u tell me reason and solution?

    • Reply
      Thyroid Advisor February 23, 2017 at 8:01 pm

      I’m a bit puzzled by what exactly you are trying to say, but regardless, diagnosing thyroid issues over the internet is very difficult and something that your doctor would know more about.

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