1. The THYROID GLAND AND GOITER: Ating Alamin

2. Butterfly-shaped organ in front of the neck
The thyroid gland is the largest organ specialized for endocrine function in the human body. It is located in the neck in front of the windpipe (trachea), below the Adam’s apple (thyroid cartilage). In adults, it can weigh up to approximately 10-20grams.

3. What Does Your Thyroid Gland Do for You?
Produces Two Hormones Called
Thyroxine (T4)
Thyronine (T3)
Regulates Metabolism so Your Cells Function Properly
Affects Every Cell in the Body
The major function of the thyroid cells is to secrete a sufficient amount of thyroid hormones, primarily tetraiodothyronine (T4) and to a lesser extent, triiodothyronine (T3). Although T4 is the major hormone produced, it is T3 that is active. The thyroid hormones promote normal growth and development and regulate a number of homeostatic functions, including energy and heat production.

4. Thyroid Hormone Affects Many Organs and General Health
Eyes
Lungs
Brain
Heart
The thyroid hormone affects all the cells in the body. We will discuss its more evident effects on our body.
Thyroid hormones increase oxygen consumption and heat production in all tissues except the brain, spleen, and testis. It contributes to the increased oxygen consumption of the whole body even at rest (basal metabolic rate). That is why in hyperthyroidism the person always feel hot even when he/she is in cool weather or environment, and the converse happens in hypothyroidism.
Thyroid hormones increase the strength of contraction or pumping power (positive inotropic effect) and the number of beats in a minute (positive chronotropic effect) of the human heart. That is why the heart beats so fast in hyperthyroidism, and slow in hypothyroidism.
Thyroid hormones stimulate the motility of our gut, which can result in increased motility and diarrhea (increased frequency of bowel movement in a day) in hyperthyroidism and slowed bowel transit and constipation in hypothyroidism.
Thyroid hormones stimulate stimulate increased production or structural proteins. In hyperthyroidism there is loss of muscle tissue, increase in the speed of muscle contraction and relaxation, the opposite in hypothyroidism. Thyroid hormones are essential for normal development of the central nervous system, and failure of the fetal thyroid function results is severe mental retardation. In adults, this is seen as hyperactivity of hyperthyroid persons and sluggishness of hypothyroid ones.
Liver
Kidney
Skin
GI Tract
Uterus

5. Brain function, memory, concentration Muscle movement
Iodine
Thyroid Hormone
Thyroid hormones are unique in that they contain 59-65% of the trace element iodine (I). Iodine is integral to the thyroid hormones’ composition, hence the name triIODOthyroinine (T3) and tetraIODOthyronine (T4). That is why too much or too little iodine result in deleterious effects.
So let’s talk about iodine.
Iodine enters the body in food or water in the form of iodide or iodate ion, the iodate ion being converted to iodide in the stomach. In the course of a million years, iodine has been leached from the soil and washed down into the oceans, so that in mountainous and inland areas the supply of iodine may be quite limited, whereas the element is plentiful in coastal areas.
The thyroid gland concentrates and traps iodide and produces and stores thyroid hormones.
The WHO recommends optimal daily iodide intake of 150micrograms for adults; for infants (up to 1year old) 50 micrograms; for children ages 1-6years 90micrograms; and for children ages 7-12 years, 120micrograms. Pregnant and breastfeeding mothers have the highest requirement, 200 micrograms, because they have to take in for themselves and their unborn infant.
If iodide intake is below 50micrograms per day, the thyroid gland is unable to make enough thyroid hormones, and the thyroid enlarges (hypertrophies) and the result is goiter and hypothyroidism.
Brain function, memory, concentration
Muscle movement
Cholesterol melting
Normal heart beat

6. Any enlargement of the thyroid gland
GOITERS
Any enlargement of the thyroid gland
“Bosyo”
Any enlargement of the thyroid gland is called goiter or “bosyo” in the vernacular. Everybody has a thyroid, but only those who have enlarged thyroid have goiter.

7. This is how a goiter looks likes

8. G O I T E R
These are also goiters that have been left unattended for several years. They are not very nice to look at.

9. GOITERS - Diffuse Structure Function - Euthyroid - Hyperthyroid
- Nodular
Function
- Euthyroid
- Hyperthyroid
- Hypothyroid
Remember! Goiter means an enlarged thyroid gland!
To further differentiate one goiter from another, we have to consider two things: structure and function. When you consider the structure of the goiter, it may be diffuse or uniformly enlarged; or it may be nodular, meaning, you can feel or see marble- or ball-like structures in the goiter itself. The first illustration of the lady facing forward has a diffuse goiter. The illustration of the man facing left and the picture of the lady also facing left is an example of nodular goiter.
When you consider function, it means that the thyroid gland may be hyperactively functioning, hence, HYPERthyroid; not functioning enough, hence, HYPOthyroid; or functioning just right or normally, hence, EUthyroid
There may be different combinations of structure and function in the thyroid. So, one may have a diffuse hyperfunctioning (toxic) goiter, diffuse hypofunctioning goiter, or diffuse but normally functioning (nontoxic) goiter. The same hold true for nodular goiters – nodular hyperfunctioning (toxic) goiter, nodular hypofunctioning goiter, or nodular but normally functioning (euthyroid) goiter.
On the other hand, the thyroid may not be enlarged at all, so there is NO goiter, but it may be hyperfunctioning (hyperthyroidism) or hypofunctioning (hypothyroidism).

10. When the Thyroid Doesn’t Work
Hyperthyroidism
Hypothyroidism
Remember hyperfunctioning thyroid = HYPERthyroidism
hypofunctioning thyroid = HYPOthyroidism
normally functioning thyroid = EUthyroidism

11. When the Thyroid Doesn’t Work
Hyperthyroidism
Too Much Thyroid Hormone
Metabolism Speeds Up
Hypothyroidism
Too Little Thyroid Hormone
Metabolism Slows Down
Hyperthyroidism = too much thyroid hormone is produced = metabolism speeds up. Everything is up or fast!
Hypothyroidism = too little thyroid hormone is produced = metabolism slows down. Everything slows down!

12. Two Common Types of Thyroid Disease
The lady on the left, has diffuse toxic goiter, also known as Grave’s disease
The lady on the right is hypothyroid. It is not evident just by looking at the picture whether she has a goiter or not
Hyperthyroidism
Hypothyroidism

13. Signs and Symptoms of Hyperthyroidism
Bulging Eyes/Unblinking Stare
Menstrual Irregularities or Light Period
Excessive Vomiting in Pregnancy
First-Trimester Miscarriage
Family History of Thyroid Disease or Diabetes
Nervousness
Irritability
Difficulty Sleeping
Swelling (Goiter)
Frequent Bowel Movements
Warm, Moist Palms
Hoarseness or Deepening of Voice
Difficulty Swallowing
Rapid or Irregular Heartbeat
Infertility
Weight Loss
Heat Intolerance
Increased Sweating
Persistent
Sore or Dry Throat

14. Signs and Symptoms of Hypothyroidism
Tiredness
Forgetfulness/Slower Thinking
Moodiness/ Irritability
Depression
Inability to Concentrate
Thinning Hair or Hair Loss
Loss of Body Hair
Dry, Patchy Skin
Weight Gain
Cold Intolerance
Elevated Cholesterol
Muscle Weakness or Cramps
Constipation
Infertility
Menstrual Irregularities/ Heavy Period
Slower Heartbeat
Difficulty Swallowing
Persistent Dry or Sore Throat
Hoarseness/ Deepening of Voice
Swelling (Goiter)
Puffy Eyes

15. What causes Thyroid Diseases ?
The “Hidden” Health Problem

16. What causes thyroid diseases ?
Iodine deficiency disorder
Surgical
Radioiodine therapy
Autoimmune diseases
What causes thyroid disease?
As explained earlier, iodine plays a very important role in the production of thyroid hormones. If iodide intake is below 50micrograms per day, the thyroid gland is unable to make enough thyroid hormones, and the thyroid enlarges (hypertrophies) and the result is goiter and hypothyroidism.
If a patient had a previous operation of the thyroid, as in total thyroidectomy, he will develop hypothyroidism because the site for thyroid hormone production has been completely removed. This is easily prevented by the prescription of thyroid hormone tablets as replacement for the lost endogenous thyroid hormones.
The same principle operates in patients who had undergone radioactive iodine therapy. Radioactive iodine (I-131) is given as treatment for diffuse toxic goiter and thyroid cancer. What it does is to “melt” the thyroid gland so that the hyperactivity ceases. In thyroid cancer it is given as an adjunct to surgery (total thyroidectomy) to “melt” thyroid tissue that is not visible to the naked eye.
In persons with autoimmune disease, what happens is that the immune system perceives the person’s own body, in this case the thyroid, as foreign and thus attacks it. There is a resultant inflammation (thyroiditis) and destruction of the thyroid gland and inadvertent release of thyroid hormones. A person is predisposed to autoimmune thyroiditis usually after a viral infection

17. Clinical Expression of Iodine Deficiency
Fetus
Neonate
Miscarriages
Stillbirths
Neurological cretinism
Impaired intellectual function
Increased perinatal mortality
Increased infant mortality
Neonatal goiter
Cretinism
Impaired intellectual function

18. Clinical Expression of Iodine Deficiency
Child & adolescent
Adult
Goiter
Hypothyroidism
Impaired intellectual function
Retarded physical development
Goiter
Hypothyroidism and poor intellectual and physical performance

20. Sources of Dietary Iodine
Iodine in soil, water and crops
Seafood
Dairy Products
Iodised salt and other fortified foods
Medicines/health foods/supplements
Other adventitious sources

21. Myths and Facts on Thyroid Diseases

22. ON FOODS Myth Eating carrots, cabbage, root crops can cause goiter.
Fact
These foods have goitrogens.
But you have to eat a truckload of these foods in a short time before you develop goiter.
This is a classic old wives tale! Eating the above-mentioned foods will not cause goiter unless you eat a truckload of them in your lifetime.

23. ON FOODS Fact Myth Drinking cold drinks is bad if you have goiter.
The temperature of the food or drink has no effect on the thyroid gland since it is not located in the alimentary tract.
The temperature of the food or drink
has no effect on the thyroid gland
since it is not located in the
alimentary tract

24. ON FOODS Myth Eating seafoods can cure goiter.
Not eating seafoods can cause goiter
Fact
Seafoods are important for their iodine content but can not cure goiter.
A person with iodine deficiency may develop goiter.
Seafoods are rich in iodine. Iodine is needed by the thyroid gland to produce thyroid hormones; and if iodine is deficient, thyroid hormone production is not sufficient and the thyroid gland may enlarge (goiter). Eating seafoods as well as iodine-enriched salt or food may help in the prevention of goiter and hypothyroidism. However, once a goiter develops, eating seafoods is not enough to cure it.
If a person is unable to eat seafoods but his food is seasoned by iodine-enriched salt, this may still be enough to supply his daily requirement of iodine such that goiter and hypothyroidism may still be prevented.

25. ON FOODS
Myth
Herbal medicines are effective in treating goiter and other thyroid problems.
Fact
Contents of herbal medicines are often not specified; their efficacy to treat is still in question.
No herbal medicine has been studied and proven to treat goiter. In addition, their safety has not been established either; and they may have may have adverse effects on a person’s kidneys and liver. It is best to seek consultation with a physician prior to taking any medications for proper direction and guidance.

26. ON FERTILITY Myth A person with goiter becomes infertile Fact
Simple goiter does not affect fertility of both sexes.
It is abnormal thyroid function that affects fertility
Remember structure and function of the thyroid gland are two entities that have to be considered. The simple enlargement of the thyroid gland (goiter) has no effect on a person’s fertility.

27. ON FERTILITY
Myth
Radioactive iodine treatment for hyperthyroidism will lead to infertility.
Fact
Radioactive iodine only concentrates in the thyroid gland and does not affect other organs

28. ON PREGNANCY Myth Bearing down during labor can cause goiter Fact
Iodine deficient pregnant women develops goiter to compensate for thyroid hormone deficiency. It is noted after delivery when increased weight is resolved

29. ON PREGNANCY Myth Goiter, if present, indicates caesarean section Fact
Bearing down during labor does not affect the size of goiter

30. ON PREGNANCY
Myth
Any drug for the treatment of thyroid problem should be discontinued once the patient becomes pregnant
Fact
If the medication is for hyperthyroidism or replacement therapy, the patient should be referred to an endocrinologist for dose adjustment

31. ON PREGNANCY
Fact
There is an increased risk for miscarriage if medications are discontinued
Fact
Patients with inadequate replacement therapy have abnormal platelet function which may lead to prolonged bleeding during labor

32. ON PREGNANCY
Myth
All mothers with thyroid diseases will deliver infants with thyroid problems
Fact
Mothers with circulating thyroid antibodies are more likely to have infants with thyroid problems
Antithyroid medications traverse the placenta and may cause transient hypothyroidism in the baby
Pregnant women who have hypothyroidism to begin with may deliver infants who are hypothyroid IF their thyroid hormone replacement dose is inadequate. This is because the thyroid begins to function in the human fetus at about 11weeks in the mother’s womb. Prior to this time, the fetal thyroid does not concentrate iodine. Hence, the fetus is completely dependent on his mother’s thyroid hormone stores. Remember! Thyroid hormones are important for early fetal brain development. If it is deficient especially during the earlier part of the pregnancy, the fetus’ nervous system will not develop optimally and the infant may be born with mental retardation of varying degrees. Thus, it is pertinent for women with hypothyroidism contemplating pregnancy or who find that they are pregnant to immediately inform their physician or endocrinologist for proper adjustment of their thyroid hormone dose. If this is done, the fetus will not develop hypothyroidism.

33. ON VARIOUS TREATMENT MODALITIES
Myth
Radioactive Iodine Treatment can cause cancer
Fact
There has been no report that it can cause cancer
There is no chromosomal abnormality in children born to mothers who received the treatment

34. ON VARIOUS TREATMENT MODALITIES
Myth
Radioactive Iodine Treatment cannot be given to individuals in their reproductive age
Fact
131 Iodine concentrates only in the thyroid gland
Fertility is affected by the abnormal thyroid functional status (hyperthyroidism or hypothyroidism)
Radioactive iodine may be given to persons in the reproductive age. However, if there is a desire for a woman to get pregnant or for a man to father a child, it is advised as a matter of precaution, to avoid undue exposure of the fetus to radiation.

35. ON VARIOUS TREATMENT MODALITIES
Myth
Radioactive Iodine Therapy leads to hypothyroidism
Fact
Even without intervention, the gland will shrink in > 10 yrs time, due to continuous inflammation and fibrosis eventually leading to hypothyroidism
The dose of radioactive iodine given is carefully calculated to achieve euthyroidism when it is being given as treatment for toxic goiter. However, over time, some patients indeed progress to hypothyroidism. This is why periodic follow up with your physician is necessary so that he may readily detect if thyroid hormone levels or stores are going down and whether you would need thyroid hormone replacement.

36. ON VARIOUS TREATMENT MODALITIES
Myth
Patients who receive Radioactive Iodine uptake and therapy should be isolated
Fact
No isolation is necessary for 131 Iodine uptake and therapy for hyperthyroidism
Only patients who receive high dose treatment for cancer should be isolated in a leaded room
Radioactive iodine (I131) is used for treatment of toxic goiter and thyroid cancer; but it is also used for diagnostic purposes, to ascertain the activity of the thyroid gland. This test is called the I-131 thyroid scan and uptake. In this test a very minute amount of radioactive iodine is used; thus the patient who undergoes this test need not be isolated.
As treatment however, especially for thyroid cancer, a high dose is given of up to 100 to 200mCi. The patients who receive this will need to be admitted in the hospital and isolated for about 4 – 5 days until the radiation count is usually <2.5mRads. When this level of radiation is achieved, the patient may be safely allowed to re-circulate in society. However, as an added precaution, no intimate and prolonged contact especially with pregnant women and children is advised.

37. SURGERY
Myth
Surgery is the ultimate treatment for all thyroid diseases
Fact
Surgery is indicated for thyroid cancer, multinodular goiter, and in big goiters causing compression symptoms
Not all thyroid disease requires surgery as treatment. There are oral medications, radioactive iodine therapy for specific indications. Your doctor knows best what the best option for your particular condition is. It is best to consult your friendly endocrinologist as to your options.

38. SURGERY Myth Patients who get operated on for goiter lose their voice
Fact
This is rare if thyroidectomy is done by an experienced surgeon
Laryngeal nerve damage is higher on reoperation
Patients who undergo thyroidectomy may develop hoarseness or may even lose their voice. This happens if the recurrent laryngeal nerve which is located posterior to the trachea, intimately associated with both thyroid lobes, is injured or severed. In the hands of an experienced surgeon, this occurs in <1% of patients who undergo thyroidectomy. And a patient is placed at higher risk for developing this particular complication if the goiter is very large and adherent to its contiguous structures, which is what happens when goiters are left unattended for a very long time. Again, it is best to seek consultation immediately when a goiter or thyroid nodule is noted.

39. “Bawal magbuhat ng mabigat habang buntis dahil magkaka-Goiter sya.”
“Kaya lumalaki ang leeg at nagka-bosyo ang buntis e dahil hindi ito marunong umire.”
“Bawal magbuhat ng mabigat habang buntis dahil magkaka-Goiter sya.”

40. When you have GOITER Visit your doctor or an endocrinologist
Blood tests and other tests like ultrasound may be requested for evaluation
Medications given should be taken regularly as prescribed

41. Leilani Mercado-Asis, MD Gabriel Jasul, MD Rosa Allyn G. Sy, MD
The Philippine College of Physicians wishes to acknowledge the following for their invaluable efforts in the preparation of this module
Nemesio Nicodemus, MD
Bien Matawaran, MD
Aimee Andag-Silva, MD
Leilani Mercado-Asis, MD
Gabriel Jasul, MD
Rosa Allyn G. Sy, MD
Committee on Advocacy & Public Relations
Philippine Society of Endocrinology and Metabolism