Your thyroid is a small gland in the front of your neck. It releases hormones that control how your body uses energy. These keep your organs running properly. But some people’s thyroids can be underactive or overactive and cause health problems.

When your thyroid doesn’t produce enough hormones to meet your body’s needs, it’s called hypothyroidism. This condition affects about 5 in 100 people age 12 and older. Most cases are mild or have few obvious symptoms. But hypothyroidism can cause you to feel tired and gain weight. You may also feel cold and have a slowed heart rate.

An overactive thyroid, or hyperthyroidism, is less common. It affects about 1 in 100 people age 12 and older. This condition can cause weight loss despite an increased appetite and a rapid or irregular heartbeat. Hyperthyroidism can cause you to be nervous or irritable. You may have trouble sleeping. Left untreated, it can lead to heart problems.

Your doctor can diagnose a thyroid problem based on your symptoms and on blood tests. These tests measure levels of thyroid stimulating hormone, or TSH, and may include thyroid antibody tests. Antibody tests can reveal whether your thyroid problem is caused by an autoimmune condition, in which your immune system attacks the thyroid.

Thyroid problems are more common in women and people older than 60. Talk with your doctor if you think you may have thyroid problems.

The thyroid gland, located in the front of the neck just below the Adam’s apple, takes iodine from the diet and makes thyroid hormone. Thyroid hormone affects a person’s physical energy, temperature, weight and mood.

Thyroid diseases generally fall into two broad groups of disorders: abnormal function and abnormal growth (nodules) in the gland. These problems are common in the general population, especially among older people and women. Most thyroid problems can be detected and treated.

Functional disorders are usually related to the gland producing too little thyroid hormone (hypothyroidism) or too much thyroid hormone (hyperthyroidism).

Benign nodules in the thyroid gland are common and do not usually cause serious health problems. These nodules occur when the cell growth within the nodule is abnormal. Nodules can occasionally put pressure on the neck and cause trouble with swallowing, breathing or speaking if they are too large. The thyroid usually functions normally even when nodules are present.

Thyroid cancers are much less common than benign nodules. With treatment, the cure rate for thyroid cancer is more than 90 percent.

A butterfly-shaped organ, the thyroid gland is located anterior to the trachea, just inferior to the larynx. The medial region, called the isthmus, is flanked by wing-shaped left and right lobes. Each of the thyroid lobes are embedded with parathyroid glands, primarily on their posterior surfaces. The tissue of the thyroid gland is composed mostly of thyroid follicles. The follicles are made up of a central cavity filled with a sticky fluid called colloid . Surrounded by a wall of epithelial follicle cells, the colloid is the center of thyroid hormone production, and that production is dependent on the hormones’ essential and unique component: iodine.

Review

The thyroid gland is a butterfly-shaped organ located in the neck anterior to the trachea. Its hormones regulate basal metabolism, oxygen use, nutrient metabolism, the production of ATP, and calcium homeostasis. They also contribute to protein synthesis and the normal growth and development of body tissues, including maturation of the nervous system, and they increase the body’s sensitivity to catecholamines. The thyroid hormones triiodothyronine (T₃) and thyroxine (T₄) are produced and secreted by the thyroid gland in response to thyroid-stimulating hormone (TSH) from the anterior pituitary. Synthesis of the amino acid–derived T₃ and T₄ hormones requires iodine. Insufficient amounts of iodine in the diet can lead to goiter, cretinism, and many other disorders.

Too Little Thyroid Hormone (Hypothyroidism)

• Depression or feeling blue
• Trouble concentrating
• Tiredness
• Dry skin and hair
• Weight gain
• Feeling cold all the time

Too Much Thyroid Hormone (Hyperthyroidism)

• Nervousness and anxiety
• Weight loss
• Tremor (shaking)
• Fast, irregular pulse
• Tiredness
• Feeling hot all the time

Checking for thyroid disease is similar to other kinds of medical evaluations. The doctor considers the patient’s medical history, examines the thyroid and may order a blood test or other diagnostic tests.

A standard physical examination of the thyroid gland is done by palpation – that is, feeling the thyroid gland. The doctor feels for the size and texture of the gland, and whether any masses or nodules are present.

Testing for Thyroid Function

There are two standard blood tests of thyroid function: the measurement of thyroid hormone, usually T4, and the measurement of thyrotropin (TSH). TSH is a hormone secreted from the pituitary gland that controls how much thyroid hormone the thyroid makes.

Abnormal blood tests usually reveal thyroid function problems and not the presence of thyroid nodules or cancer.

Testing for Nodules

If a nodule is found during the physical examination, a test called fine needle aspiration (FNA) biopsy may be done to help find out whether the nodule is cancerous or benign. In addition, a thyroid nuclear scan may help the doctor evaluate thyroid function or nodules. The scan is performed by giving the patient a radioisotope and taking a special picture to see how much of the radioisotope is taken up by the thyroid gland.

A thyroid ultrasound scan is a diagnostic test that shows a picture of the anatomy, or structure, of the thyroid gland. Ultrasound is most often used to determine if a nodule is solid or cystic. Cystic nodules, containing only fluid, are usually benign.

Ultrasound is not usually performed as a routine screening test for thyroid nodules in the general population. The reason is that small, nonpalpable ultrasound abnormalities are very common in people without evidence of thyroid disease.

Your thyroid is a butterfly-shaped gland in your neck, just above your collarbone. It is one of your endocrine glands, which make hormones. Thyroid hormones control the rate of many activities in your body. These include how fast you burn calories and how fast your heart beats. All of these activities are your body's metabolism.

Thyroid problems include

• Goiter - enlargement of the thyroid gland
• Hyperthyroidism - when your thyroid gland makes more thyroid hormones than your body needs
• Hypothyroidism - when your thyroid gland does not make enough thyroid hormones
• Thyroid cancer
• Thyroid nodules - lumps in the thyroid gland
• Thyroiditis - swelling of the thyroid

To diagnose thyroid diseases, doctors use a medical history, physical exam, and thyroid tests. They sometimes also use a biopsy. Treatment depends on the problem, but may include medicines, radioiodine therapy, or thyroid surgery.

A goiter is an unusually enlarged thyroid gland. It may happen only for a short time and may go away on its own without treatment. Or it could be a symptom of another thyroid disease that requires treatment. Goiter is more common in women than in men and especially in women before menopause.

Some common causes of goiter include:

• Hashimoto's disease
• Graves' disease
• Thyroid nodules
• Thyroiditis
• Thyroid cancer

Usually, the only symptom of a goiter is a swelling in your neck. It may be large enough that you can see it or feel the lump with your hand. A very large goiter can also cause a tight feeling in your throat, coughing, or problems swallowing or breathing.

Your doctor will do tests to see if it is caused by another thyroid disease.

Graves' disease is a condition that affects the function of the thyroid, which is a butterfly-shaped gland in the lower neck. The thyroid makes hormones that help regulate a wide variety of critical body functions. For example, thyroid hormones influence growth and development, body temperature, heart rate, menstrual cycles, and weight. In people with Graves' disease, the thyroid is overactive and makes more hormones than the body needs. The condition usually appears in mid-adulthood, although it may occur at any age.

Excess thyroid hormones can cause a variety of signs and symptoms. These include nervousness or anxiety, extreme tiredness (fatigue), a rapid and irregular heartbeat, hand tremors, frequent bowel movements or diarrhea, increased sweating and difficulty tolerating hot conditions, trouble sleeping, and weight loss in spite of an increased appetite. Affected women may have menstrual irregularities, such as an unusually light menstrual flow and infrequent periods. Some people with Graves' disease develop an enlargement of the thyroid called a goiter. Depending on its size, the enlarged thyroid can cause the neck to look swollen and may interfere with breathing and swallowing.

Between 25 and 50 percent of people with Graves' disease have eye abnormalities, which are known as Graves' ophthalmopathy. These eye problems can include swelling and inflammation, redness, dryness, puffy eyelids, and a gritty sensation like having sand or dirt in the eyes. Some people develop bulging of the eyes caused by inflammation of tissues behind the eyeball and "pulling back" (retraction) of the eyelids. Rarely, affected individuals have more serious eye problems, such as pain, double vision, and pinching (compression) of the optic nerve connecting the eye and the brain, which can cause vision loss.

A small percentage of people with Graves' disease develop a skin abnormality called pretibial myxedema or Graves' dermopathy. This abnormality causes the skin on the front of the lower legs and the tops of the feet to become thick, lumpy, and red. It is not usually painful.

Hashimoto’s disease is an autoimmune disorder that can cause hypothyroidism, or underactive thyroid. Rarely, the disease can cause hyperthyroidism, or overactive thyroid.

The thyroid is a small, butterfly-shaped gland in the front of your neck. In people with Hashimoto’s disease

• the immune system makes antibodies that attack the thyroid gland
• large numbers of white blood cells, which are part of the immune system, build up in the thyroid
• the thyroid becomes damaged and can’t make enough thyroid hormones

Thyroid hormones control how your body uses energy, so they affect nearly every organ in your body—even the way your heart beats.

What is hyperthyroidism?

Hyperthyroidism, or overactive thyroid, happens when your thyroid gland makes more thyroid hormones than your body needs.

Your thyroid is a small, butterfly-shaped gland in the front of your neck. It makes hormones that control the way the body uses energy. These hormones affect nearly every organ in your body and control many of your body's most important functions. For example, they affect your breathing, heart rate, weight, digestion, and moods. If not treated, hyperthyroidism can cause serious problems with your heart, bones, muscles, menstrual cycle, and fertility. But there are treatments that can help.

What causes hyperthyroidism?

Hyperthyroidism has several causes. They include:

• Graves' disease, an autoimmune disorder in which your immune system attacks your thyroid and causes it to make too much hormone. This is the most common cause.
• Thyroid nodules, which are growths on your thyroid. They are usually benign (not cancer). But they may become overactive and make too much thyroid hormone. Thyroid nodules are more common in older adults.
• Thyroiditis, inflammation of the thyroid. It causes stored thyroid hormone to leak out of your thyroid gland.
• Too much iodine. Iodine is found in some medicines, cough syrups, seaweed and seaweed-based supplements. Taking too much of them can cause your thyroid to make too much thyroid hormone.
• Too much thyroid medicine. This can happen if people who take thyroid hormone medicine for hypothyroidism (underactive thyroid) take too much of it.

Who is at risk for hyperthyroidism?

You are at higher risk for hyperthyroidism if you:

• Are a woman
• Are older than age 60
• Have been pregnant or had a baby within the past 6 months
• Have had thyroid surgery or a thyroid problem, such as goiter
• Have a family history of thyroid disease
• Have pernicious anemia, in which the body cannot make enough healthy red blood cells because it does not have enough vitamin B12
• Have type 1 diabetes or primary adrenal insufficiency, a hormonal disorder
• Get too much iodine, from eating large amounts of foods containing iodine or using iodine-containing medicines or supplements

What are the symptoms of hyperthyroidism?

The symptoms of hyperthyroidism can vary from person to person and may include:

• Nervousness or irritability
• Fatigue
• Muscle weakness
• Trouble tolerating heat
• Trouble sleeping
• Tremor, usually in your hands
• Rapid and irregular heartbeat
• Frequent bowel movements or diarrhea
• Weight loss
• Mood swings
• Goiter, an enlarged thyroid that may cause your neck to look swollen. Sometimes it can cause trouble with breathing or swallowing.

Adults over age 60 may have different symptoms than younger adults. For example, they may lose their appetite or withdraw from other people. Sometimes this can be mistaken for depression or dementia.

What other problems can hyperthyroidism cause?

If hyperthyroidism isn't treated, it can cause some serious health problems, including:

• An irregular heartbeat that can lead to blood clots, stroke, heart failure, and other heart problems
• An eye disease called Graves' ophthalmopathy. It can cause double vision, light sensitivity, and eye pain. In rare cases, it can lead to vision loss.
• Thinning bones and osteoporosis
• Fertility problems in women
• Complications in pregnancy, such as premature birth, low birth weight, high blood pressure in pregnancy, and miscarriage

How is hyperthyroidism diagnosed?

Your health care provider may use many tools to make a diagnosis:

• A medical history, including asking about symptoms
• A physical exam
• Thyroid tests, such as
  • TSH, T3, T4, and thyroid antibody blood tests
  • Imaging tests, such as a thyroid scan, ultrasound, or radioactive iodine uptake test. A radioactive iodine uptake test measures how much radioactive iodine your thyroid takes up from your blood after you swallow a small amount of it.

What are the treatments for hyperthyroidism?

The treatments for hyperthyroidism include medicines, radioiodine therapy, and thyroid surgery:

• Medicines for hyperthyroidism include
  • Antithyroid medicines, which cause your thyroid to make less thyroid hormone. You probably need to take the medicines for 1 to 2 years. In some cases, you might need to take the medicines for several years. This is the simplest treatment, but it is often not a permanent cure.
  • Beta blocker medicines, which can reduce symptoms such as tremors, rapid heartbeat, and nervousness. They work quickly and can help you feel better until other treatments take effect.
• Radioiodine therapy is a common and effective treatment for hyperthyroidism. It involves taking radioactive iodine by mouth as a capsule or liquid. This slowly destroys the cells of the thyroid gland that produce thyroid hormone. It does not affect other body tissues. Almost everyone who has radioactive iodine treatment later develops hypothyroidism. This is because the thyroid hormone-producing cells have been destroyed. But hypothyroidism is easier to treat and causes fewer long-term health problems than hyperthyroidism.
• Surgery to remove part or most of the thyroid gland is done in rare cases. It might be an option for people with large goiters or pregnant women who cannot take antithyroid medicines. If you have all of your thyroid removed, you will need to take thyroid medicines for the rest of your life. Some people who have part of their thyroid removed also need to take medicines.

If you have hyperthyroidism, it's important not to get too much iodine. Talk to your health care provider about which foods, supplements, and medicines you need to avoid.

What is hypothyroidism?

Hypothyroidism, or underactive thyroid, happens when your thyroid gland doesn't make enough thyroid hormones to meet your body's needs.

Your thyroid is a small, butterfly-shaped gland in the front of your neck. It makes hormones that control the way the body uses energy. These hormones affect nearly every organ in your body and control many of your body's most important functions. For example, they affect your breathing, heart rate, weight, digestion, and moods. Without enough thyroid hormones, many of your body's functions slow down. But there are treatments that can help.

What causes hypothyroidism?

Hypothyroidism has several causes. They include:

• Hashimoto's disease, an autoimmune disorder where your immune system attacks your thyroid. This is the most common cause.
• Thyroiditis, inflammation of the thyroid
• Congenital hypothyroidism, hypothyroidism that is present at birth
• Surgical removal of part or all of the thyroid
• Radiation treatment of the thyroid
• Certain medicines
• In rare cases, a pituitary disease or too much or too little iodine in your diet

Who is at risk for hypothyroidism?

You are at higher risk for hypothyroidism if you:

• 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 pernicious anemia, in which the body cannot make enough healthy red blood cells because it does not have enough vitamin B12
• Have Sjogren's syndrome, a disease that causes dry eyes and mouth
• Have type 1 diabetes
• Have rheumatoid arthritis, an autoimmune disease that affects the joints
• Have lupus, a chronic autoimmune disease

What are the symptoms of hypothyroidism?

The symptoms of hypothyroidism can vary from person to person and may include:

• Fatigue
• Weight gain
• A puffy face
• Trouble tolerating cold
• Joint and muscle pain
• Constipation
• Dry skin
• Dry, thinning hair
• Decreased sweating
• Heavy or irregular menstrual periods
• Fertility problems in women
• Depression
• Slowed heart rate
• Goiter, an enlarged thyroid that may cause your neck to look swollen. Sometimes it can cause trouble with breathing or swallowing.

Because hypothyroidism develops slowly, many people don't notice symptoms of the disease for months or even years.

What other problems can hypothyroidism cause?

Hypothyroidism can contribute to high cholesterol. In rare cases, untreated hypothyroidism can cause myxedema coma. This is a condition in which your body's functions slow down to the point that it becomes life-threatening.

During pregnancy, hypothyroidism can cause complications, such as premature birth, high blood pressure in pregnancy, and miscarriage. It can also slow the baby's growth and development.

How is hypothyroidism diagnosed?

Your health care provider may use many tools to make a diagnosis:

• A medical history, including asking about your symptoms
• A physical exam
• Thyroid tests, such as
  • TSH, T3, T4, and thyroid antibody blood tests
  • Imaging tests, such as a thyroid scan, ultrasound, or radioactive iodine uptake test. A radioactive iodine uptake test measures how much radioactive iodine your thyroid takes up from your blood after you swallow a small amount of it.

What are the treatments for hypothyroidism?

The treatment for hypothyroidism is medicine to replace the hormone that your own thyroid can no longer make. 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. Once you find the right dose, you will probably get a blood test in 6 months. After that, you will need the test once a year.

If you take your medicine according to the instructions, you usually should be able to control the hypothyroidism. You should never stop taking your medicine without talking with your health care provider first.

If you have Hashimoto's disease or other types of autoimmune thyroid disorders, you may be sensitive to harmful side effects from iodine. Talk to your health care provider about which foods, supplements, and medicines you need to avoid.

Women need more iodine when they are pregnant because the baby gets iodine from the mother's diet. If you are pregnant, talk with your health care provider about how much iodine you need.

What is thyroid cancer?

Thyroid cancer is a cancer that starts in the tissues of the thyroid. Your thyroid is a small, butterfly-shaped gland in the front of your neck. It makes hormones that control the way the body uses energy. These hormones affect nearly every organ in your body and control many of your body's most important functions. For example, they affect your breathing, heart rate, weight, digestion, and moods.

What are the different types of thyroid cancer?

There are different types of thyroid cancer; the main ones include:

• Differentiated thyroid cancer, which includes papillary cancer and follicular cancer
• Medullary thyroid cancer
• Anaplastic thyroid cancer

Who is more likely to develop thyroid cancer?

Certain people are more likely to develop thyroid cancer. Your risk is higher if you:

• Are between ages 25 and 65
• Are a woman
• Are Asian
• Were exposed to certain types of radiation, including from radiation treatments to your head or neck as a child or from a radiation emergency
• Have had a goiter (enlarged thyroid)
• Having certain genetic conditions, including certain types of multiple endocrine neoplasia
• Have a family history of thyroid cancer or thyroid disease

What are the symptoms of thyroid cancer?

Thyroid cancer may not cause symptoms at first. It is sometimes found during a routine physical exam. You may get signs or symptoms as the cancer gets bigger. The symptoms may include:

• A lump (nodule) in the neck
• Trouble breathing
• Trouble swallowing
• Pain when swallowing
• Hoarseness or other changes to your voice that do not get better

How is thyroid cancer diagnosed?

To find out if you have thyroid cancer, your health care provider may use:

• A physical exam, including checking your neck for swelling, lumps, or anything that seems unusual
• A medical history
• Thyroid tests
• Other blood or imaging tests
• A biopsy

What are the treatments for thyroid cancer?

Treatment for thyroid cancer depends on the type of cancer you have and whether the cancer has spread. Often, more than one type of treatment may be needed. The treatment options include:

• Surgery.
• Radiation therapy, including radioactive iodine therapy.
• Chemotherapy.
• Thyroid hormone therapy.
• Targeted therapy, which uses drugs or other substances that attack specific cancer cells with less harm to normal cells.
• Watchful waiting, which means that you don't get treatment right away. Your regularly checks to see if your signs or symptoms appear or change.

Cancer is a disease in which cells in the body grow out of control. When cancer starts in the thyroid gland, it is called thyroid cancer. Every year, about 12,000 men and 33,000 women get thyroid cancer, and about 900 men and 1,000 women die from the disease.

What Is the Thyroid?

The thyroid gland (also called simply the thyroid) is located in front of the neck. It looks sort of like a butterfly with one wing on each side of the neck. The thyroid is important in many ways for keeping your body healthy. It sends out certain chemicals (hormones) that help control many activities in the body, such as breathing and pumping blood. The thyroid helps children’s bodies develop as they grow up, including getting taller and putting on muscle. It helps control weight and is also involved in other functions.

What Causes Thyroid Cancer?

Scientists are not completely sure about what causes thyroid cancer, but some things that may make getting thyroid cancer more likely include—

• Getting too much radiation around the neck area, especially when you are young.
• Having certain genetic conditions inherited from parents.

What Are the Symptoms of Thyroid Cancer?

• A lump or swelling on the side of the neck is the most common symptom.
• Having trouble breathing.
• Having trouble swallowing.
• Having a hoarse voice.

These symptoms can also come from other conditions. If you have any of these symptoms, talk to your doctor right away. Don’t wait until the symptoms get worse.

How Can I Reduce My Risk for Thyroid Cancer?

To lower the risk of thyroid cancer, avoid unnecessary exposure to radiation, including radiation from medical imaging procedures, especially in young children, and especially around the head and neck.

The treatment of thyroid disease depends on many factors, including the type and severity of the thyroid disorder and the age and overall health of the patient. Treatment must be specific to each individual.

• Thyroid cancer is initially treated with thyroid surgery. Many patients also receive further treatment with iodine-131. Patients treated for thyroid cancer require lifelong thyroid hormone replacement.
• The majority of benign nodules do not require treatment. Patients with benign nodules are usually advised to have periodic follow-up examinations.
• Hypothyroidism usually requires only replacement of thyroid hormone by taking a single daily tablet at a dose adjusted to produce normal thyroid hormone levels.
• Autoimmune thyroiditis is a disorder that may cause hypothyroidism. It usually does not cause symptoms that require treatment unless hypothyroidism develops. In such cases, thyroid hormone replacement is required.
• Treatment of hyperthyroidism may include antithyroid drugs, radioactive iodine-131 or in rare cases, thyroid surgery.

You’ve probably heard of the thyroid gland, but do you know what it does? You might not give it a second thought unless something goes wrong. Thyroid trouble can cause a range of seemingly unrelated problems, including drastic changes to your weight, energy, digestion, or mood. Learn to recognize signs of thyroid disorder, so you can get treatment if needed.

The thyroid is a small but powerful butterfly-shaped gland located at the front of your neck. It controls many of your body’s most important functions. The thyroid gland makes hormones that affect your breathing, heart rate, digestion, and body temperature. These systems speed up as thyroid hormone levels rise. But problems occur if the thyroid makes too much hormone or not enough.

Nearly 1 in 20 Americans ages 12 and older has an under-active thyroid, or hypothyroidism. When thyroid glands don’t produce enough hormones, many body functions slow down. A smaller number of people—about 1 in 100—has an over-active thyroid, called hyperthyroidism. Their thyroids release too much hormone.

Thyroid problems are most likely to occur in women or in people over age 60. Having a family history of thyroid disorders also increases the risk.

Thyroid problems are often caused by autoimmune disorders, in which the immune system mistakenly attacks and destroys the body’s own cells. For example, an autoimmune disorder called Graves’ disease can cause the thyroid to be over-active, while one called Hashimoto’s disease can make the thyroid under-active.

Thyroid disorders can be hard to diagnose, because the symptoms are similar to other conditions. “Hypothyroidism can be very subtle,” says NIH’s Dr. Monica Skarulis, an expert on the thyroid. If a thyroid disorder is suspected—maybe because of a weight change or fatigue—blood tests can help to confirm the diagnosis and find its cause.

Patients with under-active thyroids can be treated with artificial thyroid hormones. Over-active thyroids are often treated with medications that reduce hormone levels.

During pregnancy, thyroid hormones can affect the health of both the mother and the developing baby. Thyroid hormone levels sometimes need to be carefully monitored and adjusted, even if the expectant mother never had thyroid problems before. After pregnancy, some women have abnormal levels of thyroid hormone for a year or more.

The thyroid gland also can be affected by cancer. Thyroid cancer usually has no symptoms. It’s sometimes first noticed as a lump in the neck—although such bumps are more likely to be harmless nodules.

“Thyroid nodules are extremely common, whereas thyroid cancer is pretty rare,” Skarulis says. A doctor can determine if a nodule is cancerous by removing and examining a tiny piece of it. If it shows signs of cancer, the nodule or even the entire thyroid will be removed.

If you notice signs of thyroid disease, talk with a health professional. Based on your family history, symptoms, and medical exam, your provider can help you decide if further testing or treatment is needed.

Symptoms of Thyroid Disorder

Hypothyroidism:

• Fatigue
• Depression
• Joint and muscle pain
• Cold intolerance
• Slowed heart rate
• Constipation
• Weight gain

Hyperthyroidism:

• Fatigue
• Nervousness or irritability
• Trouble sleeping
• Muscle weakness
• Heat intolerance or increased sweating
• Rapid and irregular heartbeat
• Frequent bowel movements or diarrhea
• Weight loss