What Causes Abnormal Total T4 Levels?

Abnormal total T4 levels can have various causes, ranging in severity from 'troubling' to 'life-threatening'. Finding the true cause means ruling out or confirming each possibility – in other words, diagnosis.

Diagnosis is usually a complex process due to the sheer number of possible causes and related symptoms. In order to diagnose abnormal total T4 levels, we could:

Research the topic
Find a doctor with the time
Use a diagnostic computer system.

The process is the same, whichever method is used.

Step 1: List all Possible Causes

We begin by identifying the disease conditions which have "abnormal total T4 levels" as a symptom. Here are eight of many possibilities (more below):

Hypopituitarism
Low Progesterone
Hyperthyroidism
Cirrhosis Of The Liver
Hypothyroidism
Iodine Need
Fluorosis*
Copper Deficiency

* symptoms can be very similar

Step 2: Build a Symptom Checklist

We then identify all possible symptoms and risk factors of each possible cause, and check the ones that apply:

much tooth staining or pitting

moderate unexplained weight gain

major joint pain/swelling/stiffness

difficulty falling asleep

weak sexual desire

normal TSH

frequent stools

having watery stools

difficulty losing weight

bulging eyes from hyperthyroidism

low HDL cholesterol level

low progesterone level

... and more than 110 others

Step 3: Rule Out or Confirm each Possible Cause

A differential diagnosis of your symptoms and risk factors finds the likely cause of abnormal total T4 levels:

Cause	Probability	Status
Low Progesterone	99%	Confirm
Iodine Need	12%	Unlikely
Hyperthyroidism	13%	Unlikely
Hypothyroidism	3%	Ruled out
Copper Deficiency	1%	Ruled out
Fluorosis**	0%	Ruled out
Cirrhosis Of The Liver	0%	Ruled out
Hypopituitarism	0%	Ruled out

* This is a simple example to illustrate the process

** Symptoms can be very similar

Arriving at a Correct Diagnosis

The Analyst™ is our online diagnosis tool that learns all about you through a straightforward process of multi-level questioning, providing diagnosis at the end.

If you indicate having had recent lab tests, The Analyst™ will ask further questions including this one:

T4 (Total). Unit: ug/dL [nmol/L]

Possible responses:

→ Don't know
→ Under 4.5 [58] (low)
→ 4.5 to 5.9 [58-76] (low - normal)
→ 6.0 to 11.5 [77-148] (normal)
→ Over 11.5 [148] (elevated)

Based on your response to this question, which may indicate having low TT4 level, having low-normal TT4 level, having normal TT4 level or having elevated TT4 level, The Analyst™ will consider possibilities such as:

Cirrhosis of the Liver

Hyperthyroidism

Hypopituitarism

When TSH and Total T4 are both low, a poorly-functioning pituitary gland is suspected.

Hypothyroidism

Progesterone Low or Estrogen Dominance

Progesterone increases sensitivity of estrogen receptors, and can therefore redirect estrogen activity and inhibit many of unopposed estrogen's undesirable side-effects, which includes interference with thyroid hormone activity.

Iodine Requirement

Low iodine intake can cause hypothyroidism in adults.

Megaloblastic Anemia / Pernicious Anemia

Pernicious anemia is associated with other autoimmune conditions such as Hashimoto's disease, a form of hypothyroidism.

Autoimmune Tendency

Copper Deficiency

There are a limited number of studies that suggest low copper levels may reduce thyroid function. In cases where hypothyroidism is not responding properly to medication, make sure that copper levels are normal.

Fluoride Toxicity

Though apparently vague and non-specific, most of the symptoms of fluoride toxicity point towards some kind of profound metabolic dysfunction, and are strikingly similar to the symptoms of hypothyroidism.

Your Total T4 Level