Blood reference ranges

April 12, 2021 Raul Garcia Pastrana

We should understand how the blood reference ranges are defined.

The majority of reference ranges are based on a bell curve. This curve always believes that 95% of the population are “normal”, 2.5% of the population are above “normal” and 2.5% of the population are below normal.

BUT NORMAL DOES NOT EQUAL HEALTHY.

The “normal” reference ranges are based on statistics. And they can change from year to year. However, humans are becoming more obese, more and more people suffer from Cardiovascular Disease. This means that the normal reference ranges are getting wider and wider.

Normal does not mean optimal.

A very clear example is TSH (Thyroid Stimulating Hormone). This is the parameter that the current medical model uses to determine if the thyroid hormone is functioning correctly.

The “normal” parameters for TSH are established between 0.5 until 5.0mlU/L.

This means that someone who has been chronic fatigue can come back with a TSH equal to 3.5 but because it is under the “normal” range this is not further investigated.

This is wrong for a number of reasons.

TSH functional range (a real optimal range) should be between 0.5 until 2.5 maximum. Anything above this should be further investigating looking for possible thyroid issues such as Hashimoto’s.
TSH is not the best parameter to investigate thyroid health. TSH is not even synthesized by the thyroid. It is synthesized in the pituitary gland. TSH targets the thyroid gland to produce T3 and T4 (the thyroid hormones).
In many cases, the TSH level can be under the “normal” range but the thyroid hormone is not capable to produce enough T3 and T4.

No wonder why so many patients with chronic fatigue symptoms are sent home after a normal TSH reading. No further investigations just sent home without a real explanation. All because the TSH reading is under the “NORMAL” range.

Remember “Normal” does not mean healthy or optimal.

A real a more comprehensive test to evaluate the thyroid should include

· TSH

· Free T3

· Free T4

· rT3 (reverse T3)

· Thyroid Peroxidase Antibody (TPO)

· Thyroglobulin Antibodies (TGA)

Because this is how the current medical model operates. Doctors are not allowed to perform further investigations such as free T3 and T4 until the TSH levels are out of the “normal” range.

In the meantime, patients are sent home ignoring their signs and symptoms. One of the symptoms associated with poor thyroid function is depression. This means that someone with an underactive thyroid could be sent home with a prescription for antidepressants without further investigations.

Antidepressants will aggravate the clinical presentation of the patient while not resolving the underlying root problem of the depression: An underactive thyroid.

Remember this is just an example. There are many other blood parameters and many other possible underlying health conditions which can be misdiagnosed if the blood reference ranges are not further examined by a health professional.

It is important to take a good case history and listen to the patient. Compare the information provided by the patient with the blood results in order to proceed in a way that will truly benefit the patient.

I guess this is why 10 minutes in the consultation of a GP is not enough…

We should understand how the blood reference ranges are defined.

The majority of reference ranges are based on a bell curve. This curve always believes that 95% of the population are “normal”, 2.5% of the population are above “normal” and 2.5% of the population are below normal.

BUT NORMAL DOES NOT EQUAL HEALTHY.

The “normal” reference ranges are based on statistics. And they can change from year to year. However, humans are becoming more obese, more and more people suffer from Cardiovascular Disease. This means that the normal reference ranges are getting wider and wider.

Normal does not mean optimal.

A very clear example is TSH (Thyroid Stimulating Hormone). This is the parameter that the current medical model uses to determine if the thyroid hormone is functioning correctly.

The “normal” parameters for TSH are established between 0.5 until 5.0mlU/L.

This means that someone who has been chronic fatigue can come back with a TSH equal to 3.5 but because it is under the “normal” range this is not further investigated.

This is wrong for a number of reasons.

TSH functional range (a real optimal range) should be between 0.5 until 2.5 maximum. Anything above this should be further investigating looking for possible thyroid issues such as Hashimoto’s.

TSH is not the best parameter to investigate thyroid health. TSH is not even synthesized by the thyroid. It is synthesized in the pituitary gland. TSH targets the thyroid gland to produce T3 and T4 (the thyroid hormones).

In many cases, the TSH level can be under the “normal” range but the thyroid hormone is not capable to produce enough T3 and T4.

No wonder why so many patients with chronic fatigue symptoms are sent home after a normal TSH reading. No further investigations just sent home without a real explanation. All because the TSH reading is under the “NORMAL” range.

Remember “Normal” does not mean healthy or optimal.

A real a more comprehensive test to evaluate the thyroid should include

· TSH

· Free T3

· Free T4

· rT3 (reverse T3)

· Thyroid Peroxidase Antibody (TPO)

· Thyroglobulin Antibodies (TGA)

Because this is how the current medical model operates. Doctors are not allowed to perform further investigations such as free T3 and T4 until the TSH levels are out of the “normal” range.

In the meantime, patients are sent home ignoring their signs and symptoms. One of the symptoms associated with poor thyroid function is depression. This means that someone with an underactive thyroid could be sent home with a prescription for antidepressants without further investigations.

Antidepressants will aggravate the clinical presentation of the patient while not resolving the underlying root problem of the depression: An underactive thyroid.

Remember this is just an example. There are many other blood parameters and many other possible underlying health conditions which can be misdiagnosed if the blood reference ranges are not further examined by a health professional.

It is important to take a good case history and listen to the patient. Compare the information provided by the patient with the blood results in order to proceed in a way that will truly benefit the patient.

I guess this is why 10 minutes in the consultation of a GP is not enough…