How to Distinguish Adrenal Fatigue from Hypothyroidism

Often times when a patient who comes in to the office complaining of sluggishness, weight gain, and moon facies, he or she is immediately diagnosed with Hypothyroidism and is given thyroid medications. What doctors often take for granted is the fact that Adrenal fatigue more or less resembles hypothyroidism. The two diseases have a lot of similar manifestations and they reveal similar laboratory results. However, thought the two closely resembles one another, they have a few unique features that will help doctors to come up with the right diagnoses.

First, we will enumerate the similarities between the two diseases. Both Adrenal fatigue and Hypothyroidism can be manifested by low energy, cold clammy hands, hypothermia, unexplained weight gain and sluggish digestion.

The distinctive features of Adrenal fatigue that is not found in Hypothyroidism are trembling, sleep disorders, irritability, sensitivity to light, depression and hypoglycemic states. The energy depletion of Adrenal fatigue can be observed at any time of the day and even if there is enough sleep. Trembling of the hands is another distinctive feature of Adrenal fatigue which cannot be seen in hypothyroidism. The Adrenal glands follows the so called Circadian rhythm, it usually has high activity in early morning or when we are asleep at night. This circadian rhythm is not observed in Hypothyroidism.

In Hypothyroidism, most physical features can’t be found in Adrenal fatigue syndrome like the moon facies, thinning of the eyebrows, persistent fatigue, and intolerance to heat, becoming less reactive to stimuli, hair loss and dry skin. There is also an absence of the knee-jerk reflex. In the laboratory point of view, there will be a decrease in all the thyroid hormones even if supplements are already given. This is called persistent hypothyroidism.

In some books, it is said that the Hypothyroidism in Adrenal fatigue is a secondary reaction due to the disruption of the Hypothalamic- Pituitary- Adrenal axis. The HPA axis is a part of the neuroendocrine system which was collectively called so because these glands regulate each other through the negative and positive feedbacks. The excess of the production of one system would lead to the inhibition of another in order to maintain homeostasis.

As the Adrenal system malfunctions, the Hypothalamus will decrease its production of Thyrotrophin – releasing hormone decreasing the production of Thyroid Stimulating Hormone in the Anterior Pituitary Glands. The result is the decrease production of T3 and T4 hormones which are the major thyroid hormones of the body. So the Thyroid panel report will reveal a decrease in TSH, T3, and T4.

Another theory is that when the Adrenal glands increase production of its hormones, especially adrenaline, the thyroid gland is inhibited. Instead of producing the normal and active thyroid hormones which are T3 and T4, the hormone that will predominate is the inactive form of T3 which is the reverse T3 hormone. As the reverse T3 levels increase, through the negative feedback inhibition, the hypothalamus will stop producing more TRH. The Active T3 and T4 will not be produced anymore causing hypothyroidism.