Written by Jill M. Paulson, M.D., ECNU
April 3, 2014
As an endocrinologist, I see patients with a wide variety of hormonal issues including thyroid disease. From talking with my patients and reading mainstream media, I have noticed that there is an abundance of misinformation regarding the thyroid. I hope to answer many common questions and dispel some of these rumors.
What is the thyroid gland?
The thyroid gland is a butterfly shaped gland that is located in the lower neck, just above your clavicles (collar bones). The thyroid makes thyroid hormones, T4 and T3 (the numbers are the number of iodine molecules attached). These hormones are converted back and forth and to other inactive thyroid hormones by an exquisitely sensitive regulation system. I tell people to think of thyroid hormone as the fuel for your body. Everyone has different amounts and if you have too much or too little, your machine (body) is not going to work as well.
What are the symptoms of hypothyroidism (too little thyroid hormone) and hyperthyroidism (too much thyroid hormone)?
Some people are very symptomatic when they are hypo- or hyperthyroid, while others are not. Every person’s body reacts differently to abnormal thyroid levels. Additionally, there are often signs that your doctor may find on physical exam that will clue them in to a possible thyroid abnormality prior to obtaining lab testing.
Symptoms of hypothyroidism, unfortunately, can mimic symptoms of many other diseases or life issues. These include:
– Fatigue
– ‘Puffiness’ in the face
– Hoarseness of the voice
– Weakness of the muscles or pain in muscles
– Sensitivity to cold
– Dry skin
– Irregular or heavier than normal menstrual periods
– Thinning hair or brittle fingernails (in severe cases, thinning of eyebrows)
– Constipation
– New onset depression or worsening of underlying depression
– Thinking that is ‘cloudy’ or memory that is impaired
– Weight gain (usually only a few pounds)
Hyperthyroid symptoms can include:
– Fatigue
– Inability to fall asleep or stay asleep
– Increased appetite
– Weight loss (despite eating more)
– Weakness of the muscles or pain in muscles
– Sensitivity to heat or sweating
– More oily skin
– Lighter than normal menstrual periods
– Thinning of the hair
– Hand tremor or feeling ‘shaky’
– Increased frequency of bowel movements or softer bowel movements
– New or increased anxiety, nervousness, and irritability
– Palpitations and shortness of breath with activity
What is the best test to screen for thyroid disease?
The best test is called a TSH (Thyroid Stimulating Hormone). The TSH is secreted by the pituitary gland, referred to as “the master gland,” which is a pea-size gland located in the skull behind the nose. The pituitary gland gets signals from higher in the brain and from thyroid hormone circulating in the body. One of its many jobs is to secrete TSH, which then signals to the thyroid gland to make more or less thyroid hormone.
I read online about other thyroid tests. Should I have my doctor check those?
Generally, TSH is sufficient by itself as a screening test. If you have a thyroid problem, then other tests will be needed.
What are thyroid antibodies?
Antibodies are proteins made by the immune system. The most common form of hypothyroidism (low thyroid) in the US is from people making antibodies against their thyroid, literally attacking their own gland. This is called Hashimoto’s thyroiditis, named after the doctor who discovered this. Over 5% of women in this country (and in some studies the numbers are even higher) have Hashimoto’s. This means that they have positive thyroid antibodies, and therefore, an autoimmune thyroid disease.
If I have thyroid antibodies, do I need to be treated?
The answer is, ‘not always’. Having thyroid antibodies does not mean that the actual functioning of the thyroid is abnormal. It means that you are at risk to develop overt hypothyroidism (low thyroid) at some point. Your risk is usually a few percent chance a year depending on many other factors. If your thyroid screening test is normal, then in general, you should not be treated. One caveat is women of childbearing age who may need thyroid replacement even if their thyroid levels appear normal. These women have a different goal of thyroid levels than the general population.
Most people who have positive thyroid antibodies and a normal TSH will be monitored by their doctor. There are exceptions to this which depend on your particular situation.
I read that kale is good for my thyroid. Should I just go crazy with kale?
The answer is no! Kale is actually what is called a goitrogen. Other than being a word that will earn you bonus points on trivia night, goitrogens are substances that actually inhibit your thyroid from taking up iodine. Iodine is used to make thyroid hormone. I have seen examples in which eating extreme amounts of kale actually worsened the thyroid function. After the kale intake was stopped, the thyroid levels improved to near normal.
So should I AVOID kale? No. Just like everything in life, do it in moderation.
Do I get enough iodine in my diet?
Outside of the United States, iodine deficiency is the most common cause of hypothyroidism in the world. However, the United States is an iodine sufficient area; over 70% of the salt in the US is iodinated. The most important population in which we worry about iodine intake is in women planning pregnancy or those who are pregnant or breast feeding. The World Health Organization recommends 150 μg/day (micrograms per day) of iodine in women planning pregnancy and 250 μg/day of iodine for pregnant women and those lactating. The Institute of Medicine has another alternative.
Most, but not all, prenatal multivitamins have iodine in them; it is important to discuss this with your OB/GYN. There is no need, and it is not recommended, to buy iodine over the counter. This can actually have negative side effects (see below).
Should I buy ‘thyroid supplements’ that I see at the vitamin stores?
The answer is no. A lot of those supplements actually have too much iodine in them. If you overload your thyroid with too much iodine, you can actually cause an opposite effect – the thyroid will temporarily stop making thyroid hormone and lead to hypothyroidism.
I think I might have a thyroid issue. What should I do?
If you have concerns about some of the symptoms above, see your primary care doctor. Depending on their evaluation and initial screening, they may choose to treat you or refer you to an endocrine specialist.
REFERENCES:
-The American Thyroid Association Frequently Asked Questions:
http://www.thyroid.org/patient-thyroid-information/faqs/
-The American Thyroid Association Guidelines
http://thyroidguidelines.net
– The Endocrine Society’s Patient Online Network- http://www.Hormone.org
– http://www.hormone.org/hormones-and-health/what-do-hormones-do/what-does-the-thyroid-gland-do
-Joint Statement by the World Health Organization and the United Nations Children’s Fund: Reaching Optimal Iodine Nutrition in Pregnancy and Lactating Women and Young Children
http://www.who.int/nutrition/publications/micronutrients/WHOStatement__IDD_pregnancy.pdf?ua=1