What is the thyroid?

Thyroid disease is a very common health problem. As many as 20 million people in America have some form of thyroid disease. It is especially common among women.
There are safe and effective medical treatments for thyroid conditions, and your doctor can help you get the right medicine for your condition. Additionally, eating a healthy, balanced diet can be part of your overall plan for good health after a thyroid disease diagnosis.
The thyroid is an organ that is part of the endocrine system. It's a small gland that sits in your throat and wraps around your windpipe. It produces hormones that control your metabolism.
Your metabolism is the system that converts food to energy that your body can use. Thyroid hormones make sure that your metabolism creates the right amount of energy for you to function normally. When it works properly, the thyroid produces and releases hormones at a steady rate.
What is thyroid disease?
If your thyroid doesn't produce the right amount of hormones, you may have a thyroid disease. If your thyroid over-produces hormones, that disease is called hyperthyroidism. When your thyroid doesn't produce enough hormones, it's known as hypothyroidism.
Hypothyroidism
Symptoms of hypothyroidism include:
- Depression
- Dry skin
- Dry or thinning hair
- Fatigue
- Joint and muscle pain
- Difficulty becoming pregnant
- Heavy or irregular menstrual periods
- Slow heart rate
- Trouble tolerating cold
- Weight gain
Various conditions can cause an under-active thyroid, including:
Thyroiditis
Inflammation or swelling of the thyroid can reduce the production of thyroid hormones. This can occur due to illness such as the flu or a bacterial infection or else as a side effect of certain medications. You may experience painful swelling around the gland.
Hashimoto's thyroiditis
Hashimoto's disease is an autoimmune condition that occurs when your body attacks and damages your thyroid. It is an inherited condition. It is the most common form of hypothyroidism.
Postpartum thyroiditis
You may observe a decrease in thyroid hormones after giving birth. This condition is usually temporary.
Iodine deficiency
Your thyroid needs iodine to produce hormones. You usually get iodine through your diet. Consequently, if you don't consume enough iodine, it can affect your thyroid. This happens most commonly if you are taking a medication that inhibits iodine absorption.
Hyperthyroidism
Symptoms of hyperthyroidism include:
- Difficulty sleeping
- Fatigue
- Frequent bowel movements
- Goiter (swelling in the neck)
- Muscle weakness
- Nervousness or irritability
- Rapid or irregular heartbeat
- Shaky hands, sweating, or trouble tolerating heat
- Weight loss despite an increased appetite
Various conditions will cause the thyroid to produce too much hormone, including:
In cases of Graves' disease, your entire thyroid gland is overactive and produces too many hormones. This condition is also called diffuse toxic goiter.
Nodules
One or more nodules within the thyroid can become overactive while the rest function normally. One overactive nodule is called a toxic, autonomously functioning thyroid nodule, while a gland with more than one overactive nodule is called a toxic multi-nodular goiter.
Thyroiditis
Inflammation of the thyroid can lead to overproduction of thyroid hormone. This can be caused by bacterial infections, illnesses such as the flu, or certain medications. You may notice swelling and pain in your throat.
Excessive iodine
If you consume too much iodine, your thyroid will use it to produce more thyroid hormones than you need. This can happen if you are taking medicines that contain high amounts of iodine.
What foods are bad for the thyroid?
There is no specific diet that will dramatically affect the symptoms of thyroid disease. Some experts suggest avoiding soy products such as tofu or soy milk if you are on medications to replace thyroid hormones in your body. Soy can interfere with how well your body absorbs the medication. Your doctor can tell you if you should limit or eliminate soy from your diet.
Unless otherwise directed by your doctor, you can eat foods that are naturally rich in iodine, even if your thyroid is hyperactive. Eating iodine-rich foods like fish and dark leafy greens is unlikely to affect how your thyroid functions.
Thyroid disease is a chronic illness that requires care and attention to your overall health, so most experts suggest eating a healthy, balanced diet to support good health. Choose a variety of fruits and vegetables, as well as foods with whole grains. Lean meats and fish are a good source of protein, as are nuts and legumes like beans. Your doctor may suggest that you increase the amount of fiber in your diet, particularly if you have digestive issues due to underactive thyroid.

QUESTION
Where is the thyroid gland located? See AnswerCan cutting out gluten help thyroid disease?
Hashimoto's disease is an autoimmune condition that causes an underactive thyroid. You may have digestive symptoms that accompany this condition. Certain foods can aggravate digestive symptoms, including foods high in gluten, sugar, or highly processed foods.
You may find that cutting back on these foods makes you feel better. You may not experience stomach discomfort as frequently. Removing gluten from your diet won't change how your thyroid functions, but you may find that it improves your quality of life.
What is a low-iodine diet for thyroid disease?
If you have a hyperactive thyroid, your doctor may prescribe radioactive iodine. This will damage some of the cells in your thyroid and lower the amount of hormone it produces. You may need to limit your iodine intake prior to starting the treatment, though, so that the medication is maximally effective.
Foods that you may need to limit for a low-iodine diet include:
- Blackstrap molasses
- Egg yolks, whole eggs, and foods containing whole eggs
- Commercially prepared bakery products that contain iodate dough conditioners
- FD&C red dye #3
- Foods that contain the additives carrageen, agar-agar, alginate, or nori
- Iodized salt
- Milk or other dairy products, including ice cream, cheese, yogurt, butter, and milk chocolate
- Seafood, including fish, sushi, shellfish, kelp, or seaweed
- Soy products, including soy sauce, soy milk, and tofu
- Vitamins or supplements that contain iodine
If you have thyroid disease, talk to your doctor about what dietary changes might make you feel better.
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Health Solutions From Our Sponsors
American Thyroid Association: "General Information/Press Room." "Low Iodine Diet."
Endocrine Web: "Gluten and Autoimmune Thyroiditis." "Thyroid Gland: Overview."
Harvard Health Publishing: "Healthy Eating for a healthy thyroid."
National Health Service: "Thyroiditis."
National Institute of Diabetes and Kidney and Digestive Diseases: "Hyperthyroidism (Overactive Thyroid)." "Hypothyroidism (Underactive Thyroid)."
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Fine-Needle Aspiration Biopsy of the Thyroid
Fine-needle aspiration biopsy of the thyroid is used to obtain tissue for analysis. Fine-needle aspiration is also performed to treat thyroid cysts. The fine-needle aspiration biopsy procedure may be recommended to make the diagnosis and/or select therapy of a thyroid nodule. Fine needle aspiration biopsy may also be recommended to drain or shrink a thyroid cyst.Hyperthyroidism
Hyperthyroidism is an excess of thyroid hormone due to an overactive thyroid gland. Symptoms can include increased heart rate, weight loss, heart palpitations, frequent bowel movements, depression, fatigue, fine or brittle hair, sleep problems, thinning skin, and irregular vaginal bleeding.
Graves' disease is the most common cause of hyperthyroidism. Many other health problems or taking excess thyroid hormone medication can cause an overactive thyroid gland. Treatment for the condition is with medication, radioactive iodine, thyroid surgery (rarely), or reducing the dose of thyroid hormone. No diet has been shown to treat hyperthyroidism or its symptoms and signs.
Hyperthyroidism: Symptoms, Treatment, Medication
What are the symptoms of hyperthyroidism? What causes hyperthyroidism? What happens when you take thyroid medication? Hyperthyroidism occurs when an overactive thyroid gland produces an excessive amount of thyroid hormone. Learn hyperthyroidism causes, symptoms, and treatment.Hypothyroidism
Hypothyroidism is any state in which thyroid hormone production is below normal. Normally, the rate of thyroid hormone production is controlled by the brain by the pituitary gland. Hypothyroidism is a very common condition and the symptoms of hypothyroidism are often subtle but may include constipation, memory loss, hair loss, and depression. There are a variety of causes of hypothyroidism, and treatment depends on the cause.Thyroid Blood Tests
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Thyroid Disorders Symptoms and Signs
Thyroid diseases and disorders are caused because the body either makes too much or too little thyroid hormones, which are necessary for vital functions of the body.Thyroid disease and disorder symptoms and signs depend on the type of the thyroid problem. Examples include heat or cold intolerance, sweating, weight loss or gain, palpitations, fatigue, dry skin, constipation, brittle hair, joint aches and pains, heart palpitations, edema, feeling bloated, puffiness in the face, reduced menstrual flow, changes in the frequency of bowel movements and habits, high cholesterol, hoarseness, brittle hair, difficulty swallowing, shortness of breath, a visible lump or swelling in the neck, tremors, memory problems, depression, nervousness, agitation, irritability, or poor concentration.
Thyroid problems are more common in women.
Thyroid Disorders
There are several types of thyroid disorders including hypothyroidism, hyperthyroidism, goiters, thyroid nodules, and thyroid cancer. Symptoms vary by condition. Diagnosis is made with blood tests, scans, ultrasound, or biopsy. Treatments depend on the disorder and can include medication or surgery.Thyroid Peroxidase Test
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