Thyroid - A Complete Guide
Do you really know about your thyroid? The thyroid gland is one of the most important glands of the endocrine system and despite its small size it plays a key role in our body! It’s a butterfly-shaped organ located in the middle of the lower neck just below the Adam’s apple and wraps around the trachea.
It has numerous functions, such as: • Metabolism • Growth and development • Nervous system development • Environmental adaptation • Thermoregulation • Gastrointestinal motility • Heart rate and contractility • Blood pressure • Breathing And many more! Thus we need to understand how important it is to have a healthy thyroid gland or control it in case of any imbalance (thyroid diseases)
HOW THE THYROID WORKS! Imagine that your thyroid works as a very well organized factory that works 24/7 in order to produce hormones and maintain balance!
• The president, is the hypothalamus that gives all the instructions and stimulates (via secretion of TRH, which represents a hormone that works as an information transmitter) the anterior hypophysis, that worsk as a vice president. The vice president gives commands directly to the thyroid (via secretion of the well-known hormone TSH). • Both hypothalamus and hypophysis are structures located inside the brain. • After that, the thyroid gland is stimulated and secretes his own hormones, T3(tri-iodo-thyronine) and T4(tetra-iodo-thyronine), that are released throught the body and reach every cell! • These hormones, T3 and T4 are very important and they are synthesized in the gland by 2 major components! 1] TYROSINE , which is an aminoacid found in the food (cheese, beef, lamb, porl, nuts, eggs, chicken, etc.) but can also be produced by the body with the help of phenylalanine. 2] IODINE, a mineral found in some foods (fish like tuna, cod) dairy products, grain products, fruits, vegetables and iodine sald. Iodine cannot be synthesized by the body and its really important to consume the daily recommended amount(for an adult is 150 mcg according to NIH) otherwise thyroid hormones (T3, T4) can NOT be produced. In several cases such as in pregnancy, women need about 50% more iodine than normal(IF NOT, the fetus can have serious health problems!) • According to all these mechanisms, now you understand that the normal function of the thyroid depends on many factors. If a step is missing or a substance is not sufficient enough there is no balance and the gland does not work properly.
RISK FACTORS • Gender, being a woman has 8-10 times higher risk of developing a thyroid disease. • Age, plays an important role. Being above 50y. old for both males and females. • Smoking, can affect the normal function of the thyroid gland due to several chemicals inside the cigarettes! • Pregnancy/post-partum period, women after having a baby have an increased risk of developing a temporary or even a chronic autoimmune thyroiditis while they are pregnant or even a year after birth. • Family or personal history it’s important! Thus if you have any autoimmune disease for example lupus(SLE), arthritis(RA), etc. you are having a higher risk for developing autoimmune thyroid disease. As well as if you are having a 1st degree relative with thyroid disease may increase your risk. • Food is always a parameter! Having a balanced diet is very important to your health in general. Moreover, there are certain foods such as soy products and other goitrogenic food that if you over consume them you are at higher risk(mostly if you have other risk factors as well.) These are radishes, broccoli, sprouts, kale, cauliflower etc. • Certain medications (ex. Lithium) • Other risk factors are, stress, chemotherapy, thyroid surgery, etc. • Most important is the IODINE! People who do not use iodized salt or living in iodine-poor regions such as in high mountain areas (Alps, Himalayas, etc.) may lead to iodine deficiency that will further affect the function of the thyroid!
DISEASES OF THE THYROID Briefly we should know how to distinguish the major thyroid problems, that involve mainly abnormal production of thyroid hormones (hypothyroidism, hyperthyroidism ).There are also other types of diseases such as goiter (abnormal enlargement of the gland) and several types of cancer that affect the thyroid gland. In this article we will focus on HYPOTHYROIDISM and HYPERTHYROIDISM. According to ATA (American Thyroid Association), an estimated 20 million Americans suffer from a thyroid disorder and up to 60% are unaware of their condition!
HYPOTHYROIDISM In this situation, the thyroid gland is not working properly, and produces lower amounts of thyroid hormones(T3, and T4). Trying to maintain a balance, the pituitary gland releases more TSH to help produce a sufficient amount of thyroid hormones but with no result! Thus there is: High TSH and Low T3, T4 .
Causes 1. Autoimmune cause, most common Hashimoto thyroiditis. (Means that your own body makes antibodies against your own thyroid) 2. After a thyroidectomy (if you undergo a thyroid surgery for total or partial removal of the gland, it can diminish its function) 3. Radiation 4. Certain therapies and medications. 5. Iodine deficiency 6. Congenital disease (newborns with a defective thyroid) 7. Pituitary disease (tumor, etc.) 8. During or after pregnancy
Symptoms The intensity of the symptomatology varies according to the level of the thyroid dysfunction! A general state of fatigue, low energy, excess need for sleep (somnolence), weight gain may appear at the beginning. Generally is a “silent disease” that develops slowly. More specific symptoms may appear later such as, • Constipation • Increase sensitivity to cold • Dry-coarse, thin hair , dry skin • Muscle weakness, muscle stiffness, joint pain • Impaired memory • Depression • Increased blood cholesterol and triglycerides • Slow heart rate (bradycardia) • Irregular or heavier menstrual periods. • Sexual dysfunction • Enlarged thyroid (goiter) • In infants: jaundice, hoarse crying etc.
Diagnosis Is simple, and is based on specific blood tests that check your TSH levels. Sometimes a thyroid ultrasound may be needed.
Treatment To help and control your thyroid there is a daily therapy with a synthetic hormone, called levothyroxine . Follow-up is very important.
HYPERTHYROIDISM In this situation the thyroid gland produces abnormally high amounts of thyroid hormones while the factory has lost the control. As a result, Low TSH, High T3, T4
Causes 1. Graves disease 2. Toxic Adenomas,(there is build up of some nodules inside the thyroid that start secreting thyroid hormones). 3. Subacute thyroiditis, an inflammation of the thyroid gland that leads to excess production of hormones. 4. Pituitary causes.
Symptoms Metabolism is one of the most important roles of the thyroid. During hyperthyroidism, metabolism is highly affected causing it to speed up. Most symptoms come from this metabolic imbalance. 1. Loose stool, or even diarrhea (because it increases the bowel motility) 2. Heat intolerance, increase sweating 3. Hair loss, thin hair 4. Irritability, anxiety, mental disturbances 5. Weight imbalance, appettite changes 6. Insomnia 7. Heart palpitations and tachycardia 8. Light menstrual periods, missed periods, infertility 9. Dizziness, shortness of breath, etc.
Diagnosis The approach is the same, blood tests to measure the levels of TSH, thyroid ultrasound, thyroid scan, in some cases radioiodine uptake test.
Treatment Possible treatments may include, anti-thyroid medication (ex. Methimazole, propylithiouracil) , radioactive iodine, beta blockers, thyroidectomy in specific cases (pregnancy, etc.).
Is an abnormal enlargement of the thyroid gland. Sometimes can be visible or even not. It can be accompanied by symptoms such as, • Difficult swalloing • Difficult breathing • Hoarsness of breath • Coughing, etc. Causes : Hashimoto disease, Grave’s disease, Iodine deficiency, pregnancy, etc. There are causes from hypothyroidism and hyperthyroidism as well.
All thyroid diseases are super important to be diagnosed as soon as possible, because thyroid gland affects many organs and systems of the body and may lead to very serious complications! Be sure, you have visited your endocrinologist at least once per year or inform your physician for any symptom or change in your life!
World thyroid day is celebrated every year at 25th of May!
Be healthy and happy!
About Author: Dr. Chrysoula Valaroutsou is a Greek medical doctor graduated from UOC (english division Constanta,Romania). She is passionate about medicine and always eager to learn more. She has lots of love and loyalty towards serving mankind.
References : www.eurothyroid.com , www.thyroid.org , www.uptodate.com , www.thyroflexasia.com , www.NIH.gov , www.webMD.com , www.mayoclinic.com ,
for the photos, www.intercoastalmedical.com , www.organsthebody.com , www.rush.edu , www.hendrickhealth.org , www.depositsphotos.com , www.gettyimages.com , www.doctablet.com , www.quit-yer-snoring.com , www.thyroidsurgery.com , www.medium.com , www.piktochart.com , www.sciencedirect.com