Thyroid Tests Come Back Within Range But Still Not Feeling Yourself?

Thyroid Tests Come Back Within Range But Still Not Feeling Yourself?

Been feeling tired and sluggish lately?  Feeling like normal day to day chores have become a lot more effort?  Are those kilos slowly creeping on even though your diet is pretty good?

Perhaps you have a thyroid disorder…  Many people have had their thyroid tested and been told that their test results are “within range” and their thyroid is fine.  People can have an underlying thyroid issue for up to ten years before it is picked up on a common Thyroid Stimulating Hormone (TSH) blood test.  Unfortunately, thyroid blood testing has a very wide “acceptable range” that patients can fall within and be told their thyroid function is “normal”.  This results in a large number of patients being overlooked for a thyroid condition.

Thyroid disorders are one of the most commonly underdiagnosed medical conditions today.  There are a variety of different thyroid disorders and these can present with varying severity.  Hypothyroidism or hyperthyroidism can manifest in patients from a range of root causes.  Some of the most common root causes of thyroid disorders include viral infections, nutrient deficiencies, toxicity, stress, genetics and poor gut function.

Many times thyroid conditions carry an autoimmune component.  Hashimoto’s disease (autoimmune hypothyroidism) and Graves’ disease (autoimmune hyperthyroidism) are the two main thyroid autoimmune conditions.

Common symptoms for Hashimoto’s disease and hypothyroidism

• Fatigue
• Low mood
• Dry skin
• Reduced libido

• Difficulty concentrating
• Constipation
• Enlarged neck / goitre
• Irregular menstruation

• Weight gain
• Food sensitivities
• Dry and brittle hair
• Heavy periods

• Intolerance to cold
• Digestive disorders
• Hair loss
• Exhaustion

Common symptoms for Grave’s disease and hyperthyroidism

• High resting heart rate
• Irritability
• Increased perspiration

• Palpitations
• Weight Loss
• Enlarged neck / goitre

• Hypertension
• Difficulty sleeping
• Shakiness

• Nervousness
• Bulging eyes
• Tremors

Thyroid Function

The Thyroid is a small gland located in the front of the neck area near the Adams apple.  It is an extremely important gland that is required for our survival.  The thyroid regulates the activity of all cells and tissues within the body and regulates our metabolism, energy levels, body temperature, brain development and brain function.  This is one gland that you want to be functioning well…

The thyroid produces the hormones thyroxine (T4) and Triiodothyronine (T3) and is regulated by the pituitary gland that excretes thyroid stimulating hormone (TSH) in to the blood.

Thyroid Hormones & Lab Test Ranges

The most common standard thyroid blood test is the TSH test.  This is often the only test performed to assess patient thyroid status in most cases.  This approach leaves many gaps in the full thyroid health picture and can allow for a dysfunctional thyroid to be missed.  The T3 and T4 blood levels should also be tested to see how much stored and active thyroid hormone is in the system, often this additional testing will uncover a requirement to treat the thyroid.  In addition, thyroid peroxidase (TPO) antibodies and TSH receptor antibodies (TRAb) should be tested in cases of suspected thyroid disorder to rule out any autoimmune component to the disease.  A patient can show a “normal” TSH for many years but may have TPO or TRAb antibodies that are causing an attack on the thyroid.  This attack can often be the main reason for the presenting symptom picture.  Unfortunately, thyroid testing other than TSH is often not routinely done when TSH is “within range”.

Thyroid Stimulating Hormone (TSH)

TSH is excreted by the pituitary gland to regulate the thyroid.  The more TSH released, the harder the pituitary is trying to stimulate the thyroid.  This is the most common thyroid blood test performed and lab test ranges are generally between 0.5 and 5.0mU/L.  Unfortunately people that fall within this range are commonly told their thyroid is fine or “a bit sluggish”.

Functionally, a test result between 1 and 1.5mU/L is ideal, with a test result over 2.0mU/L warranting further investigation into possible sub-clinical hypothyroidism.  A test result less than 0.5mU/L would deserve further investigation into hyperthyroidism.

Thyroxine (T4)

Thyroxine is the main thyroid hormone produced by the thyroid.  Thyroxine is made up of 4 molecules of iodine.  In order to be able to utilise this to deliver energy and oxygen to the cells, the body must remove one molecule of iodine, therefore converting T4 to the active form T3.  The laboratory reference range for T4 is usually 9.0 – 19.0pmol/L.  Again, these ranges are very wide, having a reading somewhere near the top half of the range is ideal, above 13.5pml/L with results in the lower portion of the range requiring further investigation into sub-clinical hypothyroidism.

Triiodothyronine (T3)

T3 is the active thyroid hormone in the body.  The thyroid produces some T3 directly with the majority coming from the conversion of T4 to T3.  Some of this process happens in the liver and requires certain nutrients.  The lab ranges for T3 are commonly between 3.0 and 6.5pmol/L.  A result of less than 4pmol/L would be indicating possible hypothyroidism with results above 6.0pmol/L warranting investigation into hyperthyroidism.

TPO antibodies   

Thyroid peroxidase (TPO) antibodies are markers of an attack on the thyroid itself.   TPO antibodies attack the thyroid and result in destruction of the gland over time.  This results in inflammation of the thyroid and raised levels are commonly seen in Hashimoto’s thyroiditis cases.  There should be no antibodies or very few (<5) antibodies present when tested, the lab ranges are 0 – 35IU/ml.  If you are showing raised TPO antibodies, autoimmune treatment protocols should be investigated.  The higher the number of antibodies, the greater the attack is on the thyroid.  It should be noted that not all Hashimoto’s sufferers will test positive for TPO antibodies, some 20-40% of patients are known as seronegative and do not register TPO antibodies.  Diagnosis would be required through a symptomatic profile and/or an ultrasound of the thyroid itself to assess physical damage.

TSH receptor antibodies

TSH receptor antibodies (TRAb) are related to Graves’ disease (hyperthyroidism) and stimulate the thyroid to enlarge and release excess thyroid hormone.  Lab tests have a range of less than 1.8U/L.  This test is commonly used to diagnose Graves’ disease and also used where a toxic multinodular goitre is active.  Any reading here would warrant further investigation into hyperthyroidism.

If you feel that you may be suffering from a thyroid condition or you have test results “within range” but outside the ideal ranges as mentioned above, it would be advisable to see a practitioner educated in thyroid health.

More information on thyroid health and information regarding our specialist naturopath consultations in both Perth, and internationally via skype please visit

See my other blog on Treating Common Root Causes of Thyroid Disorders.

To download a free Thyroid Health Checklist, visit