Dr. Sima Aidun is a Naturopathic Doctor, focusing on women's health issues from puberty to menopause. Her practice is located in Scottsdale Arizona and she serves cities of Scottsdale, Gilbert, Chandler, Tempe,mesa, Glendale, Sun City, paradise Valley, Apache Junction, Queen Creek, and the greater Phoenix area.

Hypothyroid in women

Hypothyroidism: Staggering women’s issue. Why?

Low thyroid function or hypothyroidism is seven times more common in women than men for two reasons:

1. Women tend to have more tendency to inherit genetic autoimmune thyroid disease (Hashimoto’s Disease)

2.Effect of female hormonal imbalance: Estrogen dominance, a condition common in premenopausal women, is characterized by relatively higher levels of estrogenas opposed to progesterone. Relatively higher amounts of Estrogen causes the liver to produce a protein called “Thyroid Binding Globulin” orTBG. TBG has a tendency to bind to free and active thyroid hormone, making it inactive; as a result, decreasing the level of free and active thyroid hormone in blood.

Unfortunately, the effect that estrogen dominance could have on the active thyroid hormone blood level cannot be picked up by routine blood work.

Even though low thyroid function is an overwhelmingly female issue, many American women who experience the symptoms of possible low thyroid function ( for instance: low energy, foggy brain, weight issues, high cholesterol ) are not being properly evaluated and diagnosed, especially if the blood result is within normal range.

Unfortunately some of us as physicians, tend to be influenced by herd mentality ; instead of looking at, listening to and believing in the patient; we look at and believe in the lab results

Later in this article, I will explain why blood tests are not very accurate by themselves in evaluating thyroid problems, but first let’s start with the basics :

Basic notes about thyroid gland and thyroid hormones :

Thyroid gland is one of the most important hormone producing glands in the body. It looks like a Bow-tie and is located in front of the neck. Normal thyroid gland is not always palpable.

T4 (thyroxine) is the main hormone produced by the Thyroid gland ( 93%). It is considered biologically and physiologically inactive.

T3 (triiodothyronine) is another hormone produced by the thyroid gland (7%). It is considered biologically and physiologically active.

Our body cannot function with only 7% of active hormone, it needs more: The main source of T3 is from the conversion of T4 ( inactive) to T3 ( active) outside thyroid gland and inside cells such as muscle and liver; as a result, the T3 level measured in the blood is not a representation of total body T3. The level of T3 produced inside the cells will not show up in blood test.

Symptoms of Hypothyroid:

• Fatigue, feeling cold, and weight gain: Thyroid hormone promotes the burning of the blood sugar as a fuel to produce energy. In the process of energy production the heat is produced and our metabolism increases. Then Hypothyroid, fatigue, weight gain and low body temperature will follow
• Depression, foggy brain, low concentration:Our brain is highly sensitive to thyroid hormone depletion, so patients with low levels of thyroid hormones often experience problems with mood and concentration
• Menstrual irregularity, low libido: Thyroid hormone imbalance leads to imbalances in female hormones as well
• Fertility impairment, miscarriage, premature delivery or still birth
• Elevated cholesterol: Synthesis of cholesterol as well as cholesterol absorption in the digestive system is increased in hypothyroidism
• Other symptoms such as: hoarseness, dry skin, constipation, brittle fingernails with ridging, low blood pressure, allergic disorders, hair loss, fluid retention, loss of hair on the outer edge of the eyebrows, tingling and/or numbness in extremities

Diagnosis of low thyroid function:

Blood test is ordered to directly look at the Thyroid hormones: T3 and T4, Thyroid antibodies as well as TSH. TSH ( Thyroid Binding Globulin) is a hormone produced by the pituitary gland ( in the brain). It is produced more if the Thyroid gland is being underactive, and less if Thyroid gland is overactive.

Traditionally, if levels fall within the normal range, then normal thyroid function is assumed. In the absence of any other underlying cause(s) the may explain low energy, depression and weight gain; the diagnosis of Hypochondriac might be given. Using this approach, we are diagnosing and treating the lab results but not the patient.

Limitations of blood tests as a sole method of diagnosis of low thyroid function:

• Thyroid blood concentration varies throughout the day, so the lab test is a snapshot of what is going on in the blood at one moment in time.
• Thyroid blood levels can be affected by prescription drugs, imbalances in other hormones in the body ,as well as disease processes
• The “normal” laboratory range of thyroid hormones is an arbitrary number. It simply reflects the “normal” range for 90-95% of the population.
• The arbitrarily defined normal value has actually changed over time, for instance the normal laboratory range for the free thyroxin was lowered 15 percent from 1991-2001.
• Effect of aging on Thyroid gland function: with age the ability of our thyroid to make hormones declines.
• Blood values do not represent the production of active hormone or T3 inside the cell

Final Note:

If low thyroid function is suspected in a patient with symptoms suggestive of low thyroid function, a blood test should be done. If the levels are abnormal (consistent with low thyroid function), the diagnosis is hypothyroidism and treatment should follow. If the lab results are normal, a trial of Thyroid medication preferably combination of T3 and T4 such as Armour thyroid can be started. In this case, the normal lab values will be used as a baseline and referenced later when follow up tests are done.