Goiter: Symptoms, Causes & Treatment of Enlarged Thyroid

What Is a Goiter and What Causes It?

A goiter is an enlargement of the thyroid gland that can be caused by iodine deficiency, autoimmune thyroid diseases (Hashimoto's or Graves' disease), thyroid nodules, inflammation, certain medications, or genetic factors. The thyroid may function normally, produce too much hormone (hyperthyroidism), or too little (hypothyroidism).

The thyroid gland is a small, butterfly-shaped organ located at the front of your neck, just below the Adam's apple (larynx). Despite its small size—normally weighing only about 20-25 grams—the thyroid plays a crucial role in regulating your body's metabolism through the production of thyroid hormones, primarily thyroxine (T4) and triiodothyronine (T3). These hormones influence virtually every cell, tissue, and organ in your body, controlling how quickly your body uses energy, makes proteins, and responds to other hormones.

When the thyroid gland grows larger than normal, this condition is called a goiter (also spelled "goitre" in British English). The medical term for thyroid is "thyroidea," which is why goiter is sometimes called "struma" in medical literature. A goiter can range from a barely noticeable swelling to a large mass that visibly protrudes from the neck and may cause breathing or swallowing difficulties.

Understanding what causes goiter is essential for proper treatment. The thyroid gland can enlarge for several different reasons, and identifying the underlying cause determines the most appropriate management approach. In some cases, the cause remains unknown, which is referred to as idiopathic goiter.

Iodine Deficiency

Iodine deficiency is the most common cause of goiter worldwide, affecting approximately 2 billion people globally. The thyroid gland requires iodine to produce thyroid hormones. When dietary iodine intake is insufficient, the thyroid gland works harder to capture as much iodine as possible, leading to compensatory growth. The pituitary gland releases more thyroid-stimulating hormone (TSH), which stimulates thyroid growth in an attempt to produce adequate hormone levels.

In regions where iodized salt is commonly used and seafood is regularly consumed, iodine-deficiency goiter has become relatively rare. However, it remains a significant public health problem in many developing countries and mountainous regions where iodine is scarce in the soil and food supply. The World Health Organization (WHO) estimates that about one-third of the world's population lives in areas with insufficient iodine intake.

Multinodular Goiter

Multinodular goiter, also known as nodular goiter, is characterized by the development of multiple nodules within the thyroid gland. These nodules are areas where thyroid tissue has grown independently and may produce thyroid hormones autonomously, without being controlled by TSH from the pituitary gland. This is the most common type of goiter in regions with adequate iodine intake.

The nodules can vary in size from tiny to several centimeters in diameter. When some nodules produce excess thyroid hormone, the condition is called toxic multinodular goiter, which causes hyperthyroidism. In most cases, however, multinodular goiter does not significantly affect thyroid hormone production, and the condition is termed nontoxic multinodular goiter.

Autoimmune Thyroid Diseases

Autoimmune conditions are common causes of goiter in developed countries. In these disorders, the immune system mistakenly attacks the thyroid gland, leading to inflammation and changes in thyroid function.

Hashimoto's thyroiditis is the most common autoimmune thyroid disease. The immune system produces antibodies that gradually destroy thyroid tissue, often leading to hypothyroidism (underactive thyroid). The thyroid may initially enlarge as part of the inflammatory response before eventually shrinking in later stages of the disease. Hashimoto's thyroiditis is also known as chronic lymphocytic thyroiditis.

Graves' disease causes the opposite effect—it stimulates the thyroid to produce excess hormones (hyperthyroidism). In Graves' disease, autoantibodies bind to TSH receptors and continuously stimulate thyroid growth and hormone production. This typically results in a diffuse goiter, where the entire thyroid gland is uniformly enlarged rather than having discrete nodules.

Thyroiditis (Inflammation)

Thyroiditis refers to inflammation of the thyroid gland and can cause temporary thyroid enlargement. Several types of thyroiditis exist:

• Subacute thyroiditis (de Quervain's thyroiditis): Often follows a viral infection and causes painful thyroid swelling, fever, and general malaise. The condition is usually self-limiting, resolving within weeks to months.
• Silent thyroiditis (painless thyroiditis): An autoimmune condition causing thyroid enlargement without pain. Often occurs postpartum (postpartum thyroiditis).
• Acute suppurative thyroiditis: A rare bacterial infection of the thyroid causing severe symptoms requiring antibiotic treatment.

Medications and Other Causes

Certain medications can interfere with thyroid function and cause goiter. Lithium, commonly prescribed for bipolar disorder, can inhibit thyroid hormone release and cause goiter in up to 50% of long-term users. Amiodarone, a heart medication, contains high amounts of iodine and can cause either hyper- or hypothyroidism with goiter.

Other factors that may contribute to goiter development include:

• Genetic factors: Thyroid disorders often run in families
• Pregnancy: Hormonal changes can trigger thyroid enlargement
• Radiation exposure: Previous radiation to the neck area
• Smoking: Contains thiocyanates that can interfere with iodine uptake
• Age: Risk increases after age 40

What Are the Symptoms of Goiter?

Many goiters cause no symptoms and are discovered incidentally. When symptoms occur, they may include visible neck swelling, feeling of throat tightness, difficulty swallowing or breathing, hoarseness, and coughing. Additional symptoms depend on whether thyroid function is normal, overactive (hyperthyroidism), or underactive (hypothyroidism).

The symptoms of goiter vary considerably depending on the size of the enlarged thyroid, the rate of growth, and whether the goiter affects thyroid hormone production. Many people with small goiters have no symptoms at all and may only discover the condition during a routine physical examination or imaging study performed for another reason.

When symptoms do occur, they typically relate to the physical presence of the enlarged thyroid pressing on surrounding structures, or to abnormal thyroid hormone levels. Understanding these symptoms is important for recognizing when to seek medical evaluation.

Physical Symptoms from the Enlarged Thyroid

As the thyroid gland grows, it may become visible as a swelling at the base of the neck. This is often more noticeable when you tip your head back or swallow. Some people first notice their goiter when they have difficulty buttoning their shirt collar or feel that necklaces and turtleneck clothing have become uncomfortable.

Larger goiters can cause compressive symptoms by pressing on nearby structures:

• Difficulty swallowing (dysphagia): The enlarged thyroid may press on the esophagus, making it harder to swallow food or pills
• Difficulty breathing: Pressure on the trachea (windpipe) can cause shortness of breath, especially when lying flat or with arms raised
• Hoarseness or voice changes: The recurrent laryngeal nerve, which controls the vocal cords, runs near the thyroid and may be affected
• Chronic cough: Irritation of the airways by the enlarged thyroid
• Feeling of fullness or tightness in the throat: Even without significant compression

In some cases, a large goiter may extend downward into the chest cavity behind the breastbone (substernal goiter), which can cause more severe compressive symptoms and may require surgical treatment.

Symptoms of Hyperthyroidism

If the goiter is associated with excess thyroid hormone production (hyperthyroidism), you may experience additional symptoms including:

• Unexplained weight loss despite normal or increased appetite
• Rapid or irregular heartbeat (palpitations)
• Nervousness, anxiety, and irritability
• Trembling hands
• Increased sweating and heat intolerance
• More frequent bowel movements or diarrhea
• Difficulty sleeping
• Muscle weakness
• Menstrual irregularities in women

Symptoms of Hypothyroidism

If the goiter results in reduced thyroid hormone production (hypothyroidism), symptoms may include:

• Fatigue and sluggishness
• Increased sensitivity to cold
• Unexplained weight gain
• Constipation
• Dry skin and hair
• Muscle aches and joint stiffness
• Depression and mood changes
• Memory problems and difficulty concentrating
• Heavier or irregular menstrual periods
• Elevated cholesterol levels

When Should You See a Doctor for Goiter?

You should consult a healthcare provider if you notice any visible swelling in your neck, feel a lump in your thyroid area, experience difficulty breathing or swallowing, have persistent hoarseness, or develop symptoms of hyperthyroidism or hypothyroidism. Seek immediate care if you have severe breathing difficulties.

While many goiters are harmless and require only monitoring, it's important to have any thyroid enlargement evaluated by a healthcare professional. A proper medical evaluation can determine the cause of the goiter, assess whether treatment is needed, and rule out more serious conditions such as thyroid cancer.

You should schedule an appointment with your doctor if you:

• Notice visible swelling or a lump at the base of your neck
• Feel unusual fullness or pressure in your throat
• Have difficulty swallowing food or liquids
• Experience shortness of breath, especially when lying down
• Develop hoarseness or voice changes lasting more than a few weeks
• Have symptoms suggesting hyperthyroidism or hypothyroidism
• Have a family history of thyroid disease or thyroid cancer
• Have previously received radiation treatment to the head or neck

How Is Goiter Diagnosed?

Goiter is diagnosed through physical examination, blood tests measuring thyroid hormone levels (TSH, T3, T4) and thyroid antibodies, thyroid ultrasound to assess size and detect nodules, and fine needle aspiration biopsy if nodules are present. Additional imaging such as CT or radioactive iodine scans may be needed in some cases.

Diagnosing goiter involves determining not only whether the thyroid is enlarged, but also the underlying cause and whether thyroid function is affected. A comprehensive evaluation typically includes a physical examination, laboratory tests, and imaging studies.

Physical Examination

Your doctor will examine your neck by feeling (palpating) the thyroid gland while you swallow. This allows assessment of the thyroid's size, consistency, and whether there are any nodules. The doctor will also check for enlarged lymph nodes in the neck and assess for signs of hyperthyroidism or hypothyroidism.

During the examination, your doctor will ask about your symptoms, medical history, family history of thyroid disease, medications you take, and your dietary habits (particularly iodine intake).

Blood Tests

Blood tests are essential for evaluating thyroid function and identifying potential causes of goiter:

Thyroid Ultrasound

Ultrasound is the primary imaging modality for evaluating goiter. This non-invasive, painless test uses sound waves to create detailed images of the thyroid gland. Ultrasound can:

• Accurately measure thyroid size
• Detect nodules as small as 2-3 millimeters
• Characterize nodule features (solid vs. cystic, calcifications, blood flow)
• Identify features that may suggest malignancy
• Guide fine needle aspiration biopsy
• Monitor changes over time

Fine Needle Aspiration Biopsy

If ultrasound reveals nodules with concerning features, your doctor may recommend fine needle aspiration (FNA) biopsy. This procedure involves inserting a thin needle into the nodule to collect cells for microscopic examination. FNA is typically performed in an outpatient setting, often using ultrasound guidance, and feels similar to having blood drawn.

The collected cells are examined by a pathologist to determine if they are benign, malignant, or indeterminate. Most thyroid nodules (approximately 90-95%) are benign. The FNA results help guide treatment decisions.

Additional Imaging Studies

In certain situations, additional imaging may be required:

• CT or MRI scan: Used when the goiter extends below the breastbone (substernal goiter) to assess the extent and plan treatment
• Radioactive iodine uptake and scan: Measures how much iodine the thyroid absorbs and creates an image showing functional areas; useful for evaluating hyperthyroidism and autonomous nodules
• PET scan: Rarely used, but may help in evaluating suspicious nodules or staging thyroid cancer

How Is Goiter Treated?

Treatment for goiter depends on the size, cause, symptoms, and thyroid function. Options include watchful waiting for small, asymptomatic goiters; thyroid hormone medication (levothyroxine) for hypothyroidism or TSH suppression; radioactive iodine therapy for hyperthyroidism or to shrink the goiter; and surgery (thyroidectomy) for large, symptomatic goiters or suspected cancer.

The treatment approach for goiter is highly individualized and depends on several factors including the goiter's size, whether it's causing symptoms, the underlying cause, thyroid hormone levels, and whether there's any concern for malignancy. In many cases, particularly for small, non-growing goiters with normal thyroid function, no active treatment is necessary.

Observation and Monitoring

For small goiters that aren't causing symptoms and have normal thyroid function with benign characteristics, watchful waiting with periodic monitoring may be the best approach. This typically involves:

• Regular physical examinations (every 6-12 months)
• Periodic blood tests to monitor thyroid function
• Repeat ultrasound examinations to track any changes in size

Many small goiters remain stable for years or even decades without requiring treatment. However, if the goiter grows significantly, symptoms develop, or thyroid function changes, treatment may become necessary.

Iodine Supplementation

For goiters caused by iodine deficiency, increasing iodine intake may help prevent further growth and may reduce the size of the goiter. This can be achieved through:

• Using iodized salt for cooking and at the table
• Eating iodine-rich foods (seafood, dairy, eggs)
• Taking iodine supplements if recommended by your doctor

The WHO recommends a daily iodine intake of 150 micrograms for adults, with higher amounts (250 mcg/day) during pregnancy and breastfeeding. However, it's important not to take excessive iodine supplements without medical supervision, as too much iodine can also cause thyroid problems.

Thyroid Hormone Medication

Levothyroxine, a synthetic form of the thyroid hormone T4, is used in two scenarios:

Treating hypothyroidism: If the goiter is associated with an underactive thyroid, levothyroxine replacement therapy normalizes hormone levels and relieves symptoms of hypothyroidism. This is a lifelong treatment that requires regular monitoring and dose adjustments.

TSH suppression therapy: In some cases, levothyroxine may be prescribed to suppress TSH levels, which may help prevent further growth or reduce the size of certain goiters. However, this approach is used less frequently now due to potential risks of over-treatment, particularly in older adults and those with heart disease.

Radioactive Iodine Therapy

Radioactive iodine (I-131) therapy is an effective treatment for certain types of goiter, particularly those associated with hyperthyroidism. The thyroid gland actively takes up iodine, so when radioactive iodine is administered (usually as a capsule or liquid), it concentrates in the thyroid tissue and gradually destroys overactive cells.

Radioactive iodine therapy can:

• Reduce goiter size by 40-60% over 6-12 months
• Control hyperthyroidism in Graves' disease or toxic multinodular goiter
• Eliminate autonomous nodules

A common side effect is the eventual development of hypothyroidism, which is easily managed with levothyroxine replacement. Radioactive iodine therapy is not suitable during pregnancy or breastfeeding.

Thyroid Surgery (Thyroidectomy)

Surgery may be recommended for goiters that are large enough to cause significant symptoms, suspected to contain cancer, or not suitable for other treatments. Surgical options include:

Hemithyroidectomy (lobectomy): Removal of one lobe of the thyroid, often used for benign nodules confined to one side or for small, low-risk thyroid cancers.

Total thyroidectomy: Removal of the entire thyroid gland, performed for large goiters, bilateral disease, or thyroid cancer. Patients require lifelong thyroid hormone replacement after total thyroidectomy.

Thyroid surgery is generally safe when performed by experienced surgeons, but carries risks including:

• Damage to the recurrent laryngeal nerve (causing voice changes)
• Damage to the parathyroid glands (causing low calcium levels)
• Bleeding and infection
• Need for lifelong thyroid hormone replacement

Can You Prevent Goiter from Developing?

Iodine-deficiency goiter can be prevented by ensuring adequate iodine intake through iodized salt, seafood, dairy products, and eggs. The WHO recommends 150 micrograms of iodine daily for adults. Avoiding smoking also reduces thyroid disease risk. However, goiters caused by autoimmune conditions or genetics cannot be prevented.

While not all types of goiter can be prevented, there are measures you can take to reduce your risk, particularly for iodine-deficiency goiter:

Ensure Adequate Iodine Intake

The most effective way to prevent iodine-deficiency goiter is to ensure you're consuming adequate iodine in your diet. Good dietary sources of iodine include:

• Iodized salt: The most reliable source; using iodized salt for cooking and seasoning provides sufficient iodine for most people
• Seafood: Fish (especially cod, tuna, and seaweed), shrimp, and other shellfish are excellent sources
• Dairy products: Milk, yogurt, and cheese contain iodine (varies by region)
• Eggs: Particularly the yolk
• Bread and grains: May contain iodine depending on how they're processed

Special attention to iodine intake is needed for certain populations:

• Pregnant and breastfeeding women: Need 250 mcg/day; may require supplements
• Vegans and vegetarians: May have limited iodine sources and should consider supplements
• People avoiding salt: Should ensure other iodine sources or use supplements
• Those eating primarily organic foods: Organic salt typically isn't iodized

Avoid Excessive Iodine

Paradoxically, excessive iodine intake can also cause thyroid problems, including goiter. Avoid taking high-dose iodine supplements without medical supervision. Be aware that some medications (particularly amiodarone and certain contrast agents) contain large amounts of iodine—inform your doctor if you have thyroid concerns.

Lifestyle Factors

Certain lifestyle modifications may help reduce your risk of thyroid disease:

• Don't smoke: Tobacco smoke contains thiocyanates that interfere with iodine uptake and increase the risk of thyroid disease, including goiter
• Limit goitrogenic foods: Cruciferous vegetables (cabbage, broccoli, cauliflower) contain compounds that can interfere with iodine uptake when consumed in very large amounts, though normal dietary intake is not a concern
• Regular medical check-ups: Particularly if you have a family history of thyroid disease

What Happens in the Body with Goiter?

The thyroid gland, located at the front of the neck, produces hormones (T3 and T4) that regulate metabolism in every cell of your body. When stimulated by TSH from the pituitary gland, the thyroid can grow larger. Goiter develops when this growth becomes abnormal, which may or may not affect hormone production.

Understanding how the thyroid functions helps explain why goiters develop and how they affect your body.

Normal Thyroid Function

The thyroid gland is located at the front of the neck, below the Adam's apple and just above the collarbone. It consists of two lobes connected by a thin band of tissue called the isthmus, giving it a butterfly-like shape. A normal thyroid gland is soft and often difficult to feel through the skin.

The thyroid produces two main hormones:

• Thyroxine (T4): The primary hormone produced by the thyroid; contains four iodine atoms
• Triiodothyronine (T3): The more active form; contains three iodine atoms; most T3 is converted from T4 in tissues throughout the body

These hormones affect virtually every cell in your body, regulating:

• Metabolic rate (how quickly you burn calories)
• Heart rate and blood pressure
• Body temperature regulation
• Growth and development
• Brain function and mood
• Muscle strength
• Cholesterol levels
• Menstrual cycles

The Thyroid-Pituitary Feedback Loop

Thyroid hormone production is controlled by a feedback system involving the hypothalamus and pituitary gland in the brain. When thyroid hormone levels are low, the pituitary releases thyroid-stimulating hormone (TSH), which signals the thyroid to produce more hormones and can cause it to grow. When hormone levels are adequate, TSH secretion decreases.

This feedback mechanism explains why chronic stimulation of the thyroid—whether from iodine deficiency, autoimmune stimulation, or other causes—can lead to goiter development.

Why the Thyroid Enlarges

The thyroid can grow larger through several mechanisms:

• Hyperplasia: An increase in the number of thyroid cells, often in response to TSH stimulation
• Hypertrophy: An increase in the size of individual thyroid cells
• Nodule formation: Focal areas of autonomous growth that develop independently
• Inflammation: Swelling from autoimmune or infectious processes
• Fluid accumulation: Cyst formation within nodules

The goiter may be diffuse (uniformly enlarged) or nodular (containing discrete lumps). It may affect thyroid hormone production, leading to hyperthyroidism or hypothyroidism, or hormone levels may remain normal.

Frequently Asked Questions About Goiter