Thyroid Disorder

Thyroid disorder is an umbrella term for conditions that prevent your thyroid from producing the right amount of hormones. These disorders affect millions of people, particularly women, and can cause symptoms ranging from fatigue and weight changes to mood problems and irregular heartbeat.

Table of contents

• What Is Thyroid Disorder?
• The Thyroid Gland and Its Function
• Types of Thyroid Disorders
• How Common Are Thyroid Disorders?
• Symptoms
• Causes and Risk Factors
• Diagnosis
• Treatment Options
• Living With Thyroid Disorder

What Is Thyroid Disorder?

Thyroid disorder is a general term for a medical condition that keeps your thyroid from making the right amount of hormones^[1]. The thyroid makes hormones that control how the body uses energy, affecting nearly every organ in your body and controlling many of your body’s most important functions^[2].

When your thyroid makes either too much or too little of these important hormones, it’s called thyroid disease^[6]. These disorders can range from a small, harmless enlargement of the gland that needs no treatment, to more serious conditions^[6].

The Thyroid Gland and Its Function

• Neck
• Endocrine system

Your thyroid is a small, butterfly-shaped gland located at the front of your neck under your skin^[1]. The gland is made up of two lobes connected by a small bridge of tissue called the isthmus (the tissue that joins the two parts together)^[3].

The thyroid gland is part of your endocrine system (a network of glands that produce hormones)^[1]. It produces and releases thyroid hormones, particularly thyroxine (also called T4) and triiodothyronine (also called T3)^[1]. The gland uses iodine, which is mostly absorbed from food, to produce these hormones^[3].

Your thyroid’s main job is to control the speed of your metabolism (the process of how your body transforms food into energy)^[1]. These hormones affect your breathing, heart rate, weight, digestion, and moods^[2]. All the cells in your body need energy to function, and when your thyroid isn’t working properly, it can impact your entire body^[1].

The amount of thyroid hormone produced is controlled by the pituitary gland and hypothalamus at the base of the brain^[3]. The pituitary gland produces a hormone called thyroid-stimulating hormone (TSH), which tells the thyroid how much hormone to make^[3].

Types of Thyroid Disorders

The two main types of thyroid disease are hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid)^[1]. Each type has several conditions that can cause it.

Hypothyroidism (Underactive Thyroid)

Hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormone^[3]. Nearly five percent of the population has an underactive thyroid, and more women than men suffer from the condition^[3].

Conditions that can cause hypothyroidism include:

• Hashimoto’s disease: This is a lifelong autoimmune condition that can cause an underactive thyroid. It’s the most common cause of hypothyroidism in countries with widely available iodized salt and other iodine-enriched foods^[1].
• Iodine deficiency: Your thyroid needs iodine to make thyroid hormone, so a lack of the mineral in your diet can lead to hypothyroidism. It’s the most common cause of hypothyroidism in countries that don’t have iodized salt widely available. It often causes goiter (enlarged thyroid)^[1].
• Congenital hypothyroidism: Sometimes, babies are born with a missing or underactive thyroid. About 1 in every 2,000 to 4,000 babies have congenital hypothyroidism^[1].
• Surgical removal of part or all of the thyroid^[16].
• Radiation treatment of the thyroid^[16].
• Certain medicines^[16].

Hyperthyroidism (Overactive Thyroid)

Hyperthyroidism occurs when the thyroid gland produces more thyroid hormone than the body needs^[3]. Overactive thyroid is not very common, affecting a little over one percent of the U.S. population. Just like underactive thyroid, more women than men suffer from the condition^[3].

Conditions that can cause hyperthyroidism include:

• Graves’ disease: This is a chronic autoimmune condition that causes an overactive thyroid. It’s the most common cause of hyperthyroidism^[1].
• Thyroid nodules: These are abnormal lumps on your thyroid gland. If the nodules are hyperfunctioning, they can lead to hyperthyroidism^[1].
• Excessive iodine: When you have too much iodine in your body, your thyroid makes more thyroid hormones than you need. You may develop excessive iodine by taking certain medications, like amiodarone (a heart medication)^[1].

Other Thyroid Disorders

Some conditions can cause both hypothyroidism and hyperthyroidism at different times:

• Thyroiditis: This is inflammation (swelling) of your thyroid gland. It typically causes temporary hyperthyroidism at first and then temporary or chronic hypothyroidism^[1].
• Postpartum thyroiditis: This is a relatively rare condition that affects some birthing parents after pregnancy. An estimated 5% of people may experience this in the year after giving birth. It typically causes hyperthyroidism first, followed by hypothyroidism. It’s usually temporary^[1].
• Thyroid cancer: Thyroid cancer occurs when cells in the thyroid change and multiply, and cancerous cells form nodules or growths. Thyroid cancer is uncommon, but rates have been on the rise over the last 30 years, mostly due to better detection through the use of ultrasound technology^[3].

How Common Are Thyroid Disorders?

Thyroid disease is very common. About 20 million people in the United States have some type of thyroid condition^[1]. It is estimated that one in eight women will develop thyroid problems during their lifetime^[7].

The incidence of hypothyroidism in women is 4.1 per 1,000 per year and 0.6 per 1,000 per year in men. The incidence of hyperthyroidism in women is 0.8 per 1,000 per year and much lower in men^[1].

Women are more likely than men to have thyroid issues. Clinical hypothyroidism affects one in 300 people in the United States, with a higher prevalence among female and older patients^[13]. Thyroid disorders are especially likely after pregnancy and during menopause^[7].

Hypothyroidism is common among adults age 60 and over. Up to 15 percent of adults age 70 and older have this condition^[8]. Up to 25 percent of nursing home residents have hypothyroidism^[8].

Symptoms

There are a variety of symptoms you could experience if you have thyroid disease. Unfortunately, symptoms of a thyroid condition are often very similar to the signs of other medical conditions and stages of life. This can make it difficult to know if your symptoms are related to a thyroid issue or something else entirely^[1].

Symptoms of Hypothyroidism

The symptoms of hypothyroidism can vary from person to person. Because hypothyroidism develops slowly, many people don’t notice symptoms of the disease for months or even years^[16]. At first, you may barely notice the symptoms, such as fatigue and weight gain, or you may think they are just part of getting older^[5].

Common symptoms of hypothyroidism include:

• Tiredness or fatigue^[9]
• More sensitivity to cold^[5]
• Weight gain^[5]
• Puffy face^[5]
• Constipation^[5]
• Dry skin and dry hair, or hair loss^[5]
• Hoarse voice^[5]
• Coarse hair and skin^[5]
• Muscle weakness, aches, tenderness and stiffness^[5]
• Menstrual cycles that are heavier than usual or irregular^[5]
• Thinning hair^[5]
• Slowed heart rate^[5]
• Depression^[5]
• Memory problems and difficulty concentrating^[5]
• High cholesterol^[3]
• Decreased sweating^[16]
• Fertility problems in women^[16]
• Goiter, an enlarged thyroid that may cause your neck to look swollen^[16]

Symptoms of Hyperthyroidism

Symptoms of an overactive thyroid include:

• Restlessness^[3]
• Agitation^[3]
• Tremors^[3]
• Weight loss^[3]
• Rapid heart rate or irregular heartbeat^[3]
• Sweating and intolerance to heat^[3]
• Irregular menstrual flow^[3]
• Thinning skin^[3]
• Sleep changes and difficulty sleeping^[3]
• Frequent bowel movements^[3]
• Goiter, an enlargement of the thyroid gland that resembles a large mass protruding from the neck^[3]
• Nervousness and anxiety^[23]

Older patients may experience irregular heart rhythms, heart failure, and mental confusion. Left untreated, patients can suffer from a “thyroid storm” in which high blood pressure, heart failure, and fever can lead to a critical situation requiring urgent medical care^[3].

Psychological Symptoms

In addition to physical symptoms, there can also be psychological symptoms. Abnormal thyroid levels can unsettle emotions^[21]. Examples of psychological symptoms include anxiety, low mood, difficulty sleeping, and problems with memory and concentration^[21]. Living with a physical illness can also be a cause of anxiety and low mood. For example, changes in appearance due to thyroid eye disease, hair loss and changes in weight can lead to feelings of low self-esteem^[21].

Causes and Risk Factors

Both types of thyroid disease can be caused by other diseases that affect the way the thyroid gland works^[6]. Autoimmune thyroid disease is the predominant form of thyroid dysfunction in the developed world^[15]. Although genetic and environmental factors have been implicated, its precise cause is unclear^[15].

Risk Factors

You are at higher risk for hypothyroidism if you^[16]:

• Are a woman
• Are older than age 60
• Have had a thyroid problem before, such as a goiter
• Have had surgery to correct a thyroid problem
• Have received radiation treatment to the thyroid, neck, or chest
• Have a family history of thyroid disease
• Were pregnant or had a baby in the past 6 months
• Have Turner syndrome (a genetic disorder that affects females)
• Have certain other conditions like type 1 diabetes, rheumatoid arthritis, or lupus

Factors like illness, pregnancy and stress can impact thyroid function^[7]. Poor lifestyle choices, such as an unbalanced diet, chronic stress or a lack of exercise, can disrupt your hormone balance and contribute to inflammation, potentially leading to thyroid dysfunction^[17].

Diagnosis

Thyroid disorders are very common and mainly occur in women, although anybody can be affected. With vague symptoms like feeling tired or cold, it is no wonder a thyroid disorder is often a suspect in many health problems^[7].

Your health care provider may use many tools to make a diagnosis^[16]:

• A medical history, including asking about your symptoms
• A physical exam
• Thyroid tests, such as blood tests for TSH, T3, T4, and thyroid antibody levels
• Imaging tests, such as a thyroid scan, ultrasound, or radioactive iodine uptake test

Blood Tests

The diagnosis of hypothyroidism doesn’t rely on symptoms alone. It’s usually based on the results of blood tests^[11]. The first blood test typically done to diagnose hypothyroidism measures the level of thyroid-stimulating hormone (TSH) in the blood. If it’s high, the test is done again, along with a blood test for the thyroid hormone T-4^[11].

Thyroid-stimulating hormone (TSH) blood tests are really accurate. Many people don’t realize a general thyroid function screen tests the thyroid-stimulating hormone as opposed to the actual amount of thyroid hormones. In general, this is a great measure of how the overall thyroid hormone system is functioning^[7].

If your thyroid is unable to make enough thyroid hormone (hypothyroidism), your TSH will rise quickly and stay elevated. If your thyroid makes too much thyroid hormone (hyperthyroidism), your TSH will drop to zero. In most cases, a TSH blood test is the best test to screen for thyroid problems^[7].

Treatment Options

Thyroid diseases are treatable, usually with medication^[1]. Although the effects can be unpleasant or uncomfortable, most thyroid problems can be managed well if properly diagnosed and treated^[6].

Treatment for Hypothyroidism

Treatment for hypothyroidism usually includes taking the thyroid hormone medicine levothyroxine every day^[11]. This medicine is taken by mouth and returns hormone levels to a healthy range, eliminating symptoms of hypothyroidism. You’ll likely start to feel better one or two weeks after you begin treatment^[11].

The goal of thyroid hormone treatment is to closely replicate normal thyroid functioning^[14]. Thyroid hormone is available as levothyroxine, which is biologically equivalent to your own thyroid hormone, thyroxine (T4). It is most commonly prescribed in tablet form but is now also available in gel capsule or liquid forms^[14].

About 6 to 8 weeks after you start taking the medicine, you will get a blood test to check your thyroid hormone level. Your health care provider will adjust your dose if needed. Each time your dose is adjusted, you’ll have another blood test^[16]. You’ll usually need to take the medicine for the rest of your life to prevent symptoms from returning^[14].

Patients with hypothyroidism should not be treated with triiodothyronine, alone or in combination with levothyroxine^[13]. Adding triiodothyronine is not recommended, even in patients with persistent symptoms and normal levels of thyroid-stimulating hormone^[13].

Treatment for Hyperthyroidism

The 3 main treatments for hyperthyroidism are^[12]:

• Medicine: Medicines called thionamides are commonly used to treat an overactive thyroid. They stop your thyroid producing excess hormones. The main types used are carbimazole and propylthiouracil. You’ll usually need to take the medicine for 12 to 18 months^[12].
• Radioactive iodine treatment: This is a type of radiotherapy used to destroy the cells in the thyroid gland, reducing the amount of hormones it can produce. It’s a highly effective treatment that can cure an overactive thyroid. You’re given a drink or capsule that contains iodine and a low dose of radiation, which is absorbed by your thyroid. Most people only need a single treatment^[12].
• Surgery: Occasionally, surgery to remove all or part of your thyroid may be recommended. This may be the best option if your thyroid gland is severely swollen or you have severe eye problems. Removing all of the thyroid gland is usually recommended because it stops the symptoms of hyperthyroidism coming back^[12].

Treatment During Pregnancy

Women with hypothyroidism who become pregnant should increase their weekly dosage by 30% up to nine doses per week (that is, take one extra dose twice per week), followed by monthly evaluation and management^[13]. If hypothyroidism is not treated during pregnancy, it can cause complications, such as premature birth, high blood pressure in pregnancy, and miscarriage. It can also slow the baby’s growth and development^[16].

Living With Thyroid Disorder

There is no way to cure or slow the progression of thyroid disease for most people. But if you are one of the 20 million Americans affected, you can manage the condition. The best approach is to get a diagnosis, prevent it from becoming a big problem, and take measures to decrease its impact on your body and your life^[7].

Taking Your Medication

It is essential to take your medication regularly as taking tablets inconsistently can affect your thyroid hormone levels and may cause you to feel worse^[21]. Sometimes it may feel as if your medication is not really working. Levothyroxine, for example, can take several months to take full effect so it is important you remain on the course of medication for it to work effectively^[21].

The only safety concerns about taking thyroid hormone are taking too much or too little. Your thyroid function will be monitored by your physician to keep your levels at the goal range^[14].

Self-Care and Lifestyle

Factors like illness, pregnancy and stress can impact thyroid function. Managing your overall health can reduce symptoms. Exercising each day and maintaining healthy relationships can help your thyroid^[7].

Preventive measures like proper nutrition, healthy lifestyle choices, stress management and regular checkups with your doctor can help reduce your risk of thyroid disorders and support optimal thyroid function^[17].

Some tips for self-care include^[21]:

• Open communication with people around you about how you feel and what you need
• Making time for activities that help you relax
• Regular exercise that is appropriate to your condition
• Eating a balanced diet
• Getting sufficient sleep

Diet Considerations

There are no specific foods or dietary supplements that you can use to treat your thyroid disorder. It is important to eat the right variety of foods in the correct proportions. Having a balanced diet is the best way to ensure your body gets all the nutrients it needs^[18].

Certain foods may affect thyroid function. You should avoid products such as kelp and sea moss as they may interfere with thyroid function and wellbeing. Kelp supplement is derived from seaweed and is naturally high in iodine, but it is of no health benefit to people with a diagnosed thyroid disorder^[18].

Monitoring and Follow-Up

For most people, psychological symptoms improve as the thyroid disorder is brought under control^[21]. However, if you still feel unwell, your doctor may be able to undertake further investigations to see whether there is something else going on with your health^[21].

Patients with persistent symptoms after adequate levothyroxine dosing should be reassessed for other causes or the need for referral^[13]. It is also common for people to feel emotionally out of sorts for some time, even once their blood tests return to normal^[21].