Thyroid Fact Sheet

by | Nov 26, 2016 | Conditions, Hormone Replacement, Thyroid

Thyroid is the major metabolic hormone.  It increases energy metabolism, blood flow, speed of thinking, intestinal motility, HDL (good) cholesterol and immune defenses.  Thyroid hormone decreases diastolic blood pressure, “waste products” of the cells, fluid accumulation and LDL (bad) cholesterol.

  • Thyroid hormones have direct effects on many body systems including the cardiovascular, nervous, digestive, and immune systems.
  • There are two major thyroid hormones, thyroxine (T4) and triiodothyronine (T3).  T4 is the most abundant thyroid hormone in the body, but it must be broken down to T3 to become active.   T3 is the “active” thyroid hormone and is widely distributed throughout the body.
  • Thyroid hormone deficiency can occur at any stage of life for a variety of reasons; thyroid hormones can also decrease naturally with age.

Signs and Symptoms of Low Thyroid Hormone (Hypothyroidism)

There are multiple physical and mental effects that may happen if the thyroid hormone levels are low, listed below are some common signs:


  • Fatigue, sluggishness, especially in the morning
  • Weight gain and trouble losing weight
  • Swelling or “puffiness” due to a condition of low thyroid hormone called “myxedema”
  • Intolerance to heat and cold, poor circulation
  • Dry, thinning hair, dry skin, brittle nails
  • Constipation, abdominal bloating, poor appetite
  • Headaches, ringing in the ear
  • Muscle aches and joint stiffness


  • Depression
  • Sleepiness, excessive snoring
  • Slow thinking or “brain fog”
  • Poor memory and concentration
  • Lack of interest in activities


Requirements for monitoring thyroid therapy:

  • Routine office visits and necessary labwork including thyroid stimulating hormone (TSH), T3 and T4 levels. Other blood levels related to thyroid hormones if needed such as reverse T3, thyroid antibodies or thyroglobulin.
  • Thyroid ultrasound in some cases.


  • Dessicated Thyroid, T4/T3 combination – Includes a balance of T3 and T4 made naturally from animals. This form of thyroid replacement is easily tolerated and provides a consistent 24-hour blood level.  (e.g. Armour, Nature-throid, Westhroid, NP thyroid)
  • Synthetic T4 – Must be broken down in the body to T3 to become active, it can stay in the form of T4, which reduces its therapeutic effect. (e.g. Synthroid, Levoxyl, Levothyroxine)
  • Synthetic T3 – This is the “active” thyroid hormone but synthetic T3 can result in a high morning/ low evening blood level. (e.g. Cytomel, Liothyronine)
  • Time released T3 (methocel) is our preferred form of T3 prescription, available from compounding pharmacies

Signs and Symptoms of Too Much Thyroid (Hyperthyroidism)

Common Complaints:

  • Nervousness, anxiety, irritability, and an inner feeling of “trembling”
  • Early morning waking and sleep disturbances
  • Fast heart rate and heart palpitations
  • Excessive weight loss despite normal calorie intake
  • Excessive hunger and thirst
  • Excessive sweating or feeling “overheated”

Risks, Contraindications and Benefits of Treatment


  • Osteoporosis or thinning of the bones, particularly when too much thyroid is replaced
  • Over-stimulation of the heart


  • Presence of other uncorrected hormone deficiencies such as a cortisol deficiency
  • Recent myocardial infarction or uncontrolled heart disease.  Treatment can still be helpful but extra caution must be used when starting thyroid hormone replacement.


  • Progressive improvement or resolution of experienced symptoms of hypothyroidism
  • Improved immune system function can help prevent infections and certain types of cancer
  • Better quality of life, especially when treatment is combined with proper nutrition and regular exercise
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