Healthy Living

If you say diabetes or breast cancer, everyone automatically knows what you are talking about. But if you mention thyroid disease, sometimes all you get is a blank stare.

But the fact is that thyroid disease is very prevalent, so since January is national Thyroid Awareness Month, it is an opportune time to educate people about the disease, its signs and symptoms.

The thyroid gland is located in your neck, right below the Adam’s Apple, over the trachea (or windpipe).  It produces two hormones, thyroxine and triiodothyronine (T4, T3 for short).

T3 is produced in small quantities by the thyroid, but is made in the rest of the body from T4.  It is ultimately responsible for the thyroid effects on our bodies.  T3 is essential for the differentiation of cells and for the coordinated growth of cells. 

In warm-blooded animals (including humans), T3 also stimulates heat production to maintain body temperature.  In babies and children, the lack of a thyroid hormone impedes growth and maturation, even though they also have trouble maintaining body temperature.  In adults, a lack of or excess of thyroid hormones  is associated with reduced or excess heat production, and the function of many organs, particularly the heart, brain, kidney, muscles, skin and digestive tract is also reduced or increased in similar proportion.

Patients with underactive thyroids will have low energy, drowsiness, slow heart, dry skin, muscle stiffness, and tend to be cold.  On the other hand, patients with excess thyroid hormones will be overactive, heat intolerant, sweaty, nervous, insomniac, and have palpitations, accelerated bowel movements and other symptoms.

The thyroid can be the target of a variety of diseases that could reduce or increase its activity or simply cause growth, inflammation, nodules (lumps) and benign or malignant tumors (cancer).

 

The most common form of thyroid disease is autoimmunity.  Our immune system protects us from bacteria, viruses and foreign proteins, but this system must learn how to recognize the components of our own bodies. This “learning” occurs in our fetal life and often – probably for genetic reasons – it does not occur properly and the system fails to recognize some cells or tissues generating a broad spectrum of diseases such as lupus, rheumatoid arthritis, pernicious anemia, type I diabetes and many others.

 

Autoimmune thyroid disease may cause a chronic inflammation of the gland known as Hashimoto’s disease, which often leads to an underactive gland, growth or nodules.

The immune system may also produce antibodies that stimulate the thyroid and cause hyperthyroidism or Graves’ disease, both of which can affect the eyes and cause them to bulge. Non-immune thyroid nodules and tumors are also frequent.  Most of the time these lumps are benign, but in roughly 10% of cases they may be cancerous. 

 

Symptoms of thyroid malfunction are often not specific. Depression, for example, may cause an array of symptoms suggestive of hypothyroidism.  A common misconception is that hypothyroidism causes obesity. While patients with hypothyroidism frequently have difficulty losing weight, patients with hypothyroidism seldom become obese.

Thyroid diseases are frequent and often complicated.  The appropriate diagnosis and treatment require a deep knowledge of thyroid physiology and pathology.  Thyroid disease may impact peoples’ lives in many ways.  Patients with hypothyroidism tend to blame this condition for most of their symptoms, which frequently result from other causes.  This may lead to erroneous changes in the dose of thyroid medication.  

Jorge E. Silva is the medical director of the Backus Center for Endocrinology, Diabetes and Metabolism. This advice should not replace the advice of your personal healthcare provider. To comment on this column or others, visit the Healthy Living blog at www.healthydocs.blogspot.com or e-mail Dr. Silva or any of the Healthy Living columnists at healthyliving@wwbh.org.