Borderline Low Thyroid Symptoms

The thyroid is a gland positioned at the bottom of the neck and shaped like a butterfly. Its main function is to control metabolism, determining how much energy the body's cells use and controlling body temperature, heart rate and the production of proteins. When a person's thyroid is functioning below optimum level, he may experience symptoms such as hair loss, stiff joints, weight gain, constipation, fatigue and an intolerance to cold.

Borderline Low Thyroid vs. Hypothyroidism

Hypothyroidism is diagnosed by the TSH, or thyroid stimulating hormone, blood test, according to the Cleveland Clinic website 25. Thyroid stimulating hormone is the hormone that stimulates the thyroid to function. The reference range, the numbers used as parameters to decide the normal values of a lab test, vary from lab to lab. Typically the range is between 0.5 and 5.0, indicating normal values of thyroid stimulating hormone and, therefore, normal thyroid function. In 2002 the American Association of Clinical Endocrinologists recommended that physicians begin treating patients whose thyroid function fell outside the narrower range of 0.3 to 3.0 to help catch patients who have mild or borderline hypothyroidism and either monitor the situation or begin treatment 125. The AACE believes borderline hypothyroidism patients, whose symptoms can be mild and vague, will benefit from this narrowing of the reference ranges with more accurate diagnosis and treatment of symptoms 25.

Potential Symptoms

Hypothyroidism produces symptoms such as fatigue; constipation; numbness and tingling in hands and feet; an intolerance to cold; dry, coarse, thin hair; decreased sexual interest; weight gain; forgetfulness; and sometimes goiter 25. With borderline hypothyroidism, or hypothyroidism in its earliest stages, few symptoms may be experienced because the body will compensate for the drop in thyroid hormones by stimulating more and keeping up for a while 25. Often symptoms of borderline hypothyroidism are experienced before thyroid function blood tests detect any changes 25.


According to, many claims of specific dietary changes and guidelines exist for hypothyroidism 235. Unfortunately those claims are false. There are no specific foods that have been shown to stimulate thyroid production and decrease mild hypothyroidism symptoms 25. does report that such foods as walnuts, cottonseed meal, soybean flour, certain calcium and iron supplements, as well as certain antacids, can interfere with the absorption of synthetic thyroid hormone and should be considered when taking thyroid hormone replacement therapy 3.

Basal Body Temperature

Because blood tests are not always accurate and symptoms of mild hypothyroidism can be vague, some physicians consider using basal body temperature as further information to help diagnose and treat hypothyroidism or borderline hypothyroidism 245. Dr. Shames of believes that some patients whose TSH levels are within normal range but still suffer from hypothyroid symptoms should take their basal body temperature over a consecutive 10-day period 4. Temperature should be taken with a basal thermometer, under the arm, first thing in the morning before rising for any reason. This information gives valuable clues as to the thyroid's ability to control the body's furnace, one of the thyroid's more basic functions. Dr. Shames uses that information in conjunction with other clinical and subjective information to help diagnose and treat hypothyroid patients of all levels.

Borderline Hypothyroidism and High Cholesterol

A decrease in thyroid function can cause the body to begin retaining cholesterol and other lipids, increasing cholesterol levels in the blood and causing hyperlipidemia. While lowering cholesterol levels is important, correcting the borderline hypothyroidism first may in turn correct the increased cholesterol levels with no need for additional medication 25. Dr. Zoe of the Living Naturally website suggests just that 5.