Thyroid Problems

What is the thyroid?

The thyroid gland, often simply called the thyroid, is a butterfly-shaped organ located at the front of the neck just below the larynx (voice box). It consists of two lobes that wrap around the windpipe (trachea) and serves as a vital member of the endocrine system, a network of hormone-producing glands. Another central player in this system is the pituitary gland, which sits at the base of the brain and governs hormone release. This gland manufactures hormones that regulate essential bodily functions such as heart rate, blood pressure, body temperature, and weight control. In response to thyroid-stimulating hormone (TSH) from the pituitary, the thyroid produces triiodothyronine (T3) and thyroxine (T4). Once formed, these hormones enter the bloodstream to reach and act on specific target tissues. When the thyroid fails to work properly, whether by underproduction or overproduction of hormones, it can lead to various serious health issues. Approximately 14% of Australians have a confirmed thyroid disorder, and another 4% (just over one million people) remain undiagnosed. These conditions affect women about ten times more often than men. Although thyroid disease typically requires lifelong management, effective treatments are available that allow individuals to maintain a normal, healthy life.

Common thyroid problems

Any dysfunction of this gland disrupts hormone balance and can lead to diverse health effects. The thyroid can malfunction in two primary ways: Hypothyroidism (insufficient hormone synthesis) Hyperthyroidism (excessive hormone secretion) Since these terms share similar sounds, it helps to recall that the prefix hypo- means “low” or “below”, whereas hyper- means “high” or “above”. Each condition affects the body differently, so the symptoms correspond to the specific disorder.

Hypothyroidism

Hypothyroidism is defined by an underactive thyroid that fails to secrete adequate hormones. This shortfall slows the basal metabolic rate, often resulting in weight gain. In Australia, this is the most prevalent thyroid issue, affecting one in thirty-three people. It occurs more often in women than men and is more common in those over 60 years of age2. The leading cause is the autoimmune disorder Hashimoto’s disease.

Signs and symptoms of hypothyroidism

Signs and symptoms of hypothyroidism can emerge gradually over several years and sometimes go unnoticed. When they present, they can include:3

• Weight gain
• Persistent fatigue
• Bradycardia (slow heart rate)
• Muscle aches and stiffness
• Difficulty with concentration or memory lapses
• Headaches
• Dry, cool skin
• Heightened cold intolerance
• A pale, puffy face
• Brittle hair and nails, thinning hair
• Constipation
• Menstrual periods that are heavier than normal
• Depression

What causes hypothyroidism

An underactive thyroid results when the gland cannot produce enough hormone. Contributing factors include:

• Hashimoto’s disease, an autoimmune attack on the thyroid
• Thyroiditis, inflammation by viral or bacterial infection
• Iodine deficiency, since iodine is essential for hormone production
• A congenitally non-functioning gland, affecting about 1 in 1,400 newborns
• Post-partum thyroiditis, a usually temporary form seen in 5%, 9% of women after childbirth5
• Surgical removal of part or all of the thyroid
• Radiation therapy aimed at head and neck cancers
• Medications containing lithium (used in psychiatric treatment)6 or certain cancer immunotherapies7

Complications of hypothyroidism

Possible complications8 of hypothyroidism include:

• Goitre, enlargement of the thyroid gland, which may alter appearance and cause difficulty swallowing or breathing
• Heart problems, such as heart disease and heart failure
• Mental health issues, including slowed cognition and depression
• Peripheral neuropathy, nerve damage resulting in pain, numbness, or tingling in the extremities
• Infertility and birth defects
• Myxoedema, a rare but life-threatening state marked by severe drowsiness, profound lethargy, and eventual unconsciousness, typically arising from long-term undiagnosed hypothyroidism

Hyperthyroidism

Hyperthyroidism (also termed thyrotoxicosis) arises when the thyroid gland is overly active and secretes excessive amounts of hormone. This surge in hormones accelerates metabolism, often causing unintentional weight loss or a fast heartbeat. It’s estimated that hyperthyroidism affects about 3 in 1,000 people in Australia.4 The most frequent trigger locally is the autoimmune condition Graves’ disease.

Signs and symptoms of hyperthyroidism

The presentation can vary, but common indicators include:

• Unintentional weight loss
• Feelings of anxiety or nervousness
• Heart palpitations
• Shortness of breath
• Persistent tiredness
• Increased appetite
• Poor tolerance of heat
• Excessive sweating
• A noticeable enlargement of the thyroid (goitre) as a lump or swelling in the neck
• Tremors or shakiness
• Changes in bowel movements or menstrual bleeding
• Thin, delicate skin
• Fine, brittle hair
• Difficulty sleeping

What causes hyperthyroidism

Conditions that may drive excessive thyroid hormone production include:

• Graves’ disease, the most common autoimmune cause
• Thyroiditis, inflammation causing hormone leakage
• Excessive iodine intake
• Non-cancerous nodules or lumps on the thyroid

Complications of hyperthyroidism

Possible complications of hyperthyroidism9 include:

• Cardiovascular issues such as rapid heart rate and atrial fibrillation (an irregular heartbeat), which elevate your risk of stroke and heart failure
• Bone weakening, leading to osteoporosis and a greater chance of fractures
• Eye disturbances like exophthalmos (bulging eyes), swelling, light sensitivity, and blurred vision
• Thyrotoxic crisis, a sudden, severe worsening of symptoms that constitutes a medical emergency, potentially causing fever, a racing pulse, and confusion. Seek urgent care if this occurs

Who faces a greater risk for thyroid disorders?

Although thyroid issues can occur in anyone, certain individuals are more susceptible, including those who:

• Have a family history of thyroid disease
• Use medications rich in iodine or consume excessive iodine supplements
• Are aged over 60
• Are female
• Have previously undergone surgery or radiation for thyroid conditions or thyroid cancer
• Live with an autoimmune disease such as type 1 diabetes or coeliac disease
• Have been pregnant or given birth within the past six months

When to visit your doctor

If you observe any persistent signs of hypo- or hyperthyroidism that cannot be explained by other causes, it’s important to consult your physician. This is especially critical if you belong to a higher-risk group.

How are thyroid problems diagnosed?

Because many thyroid symptoms overlap with those of other conditions, a combination of tests is typically required to confirm a diagnosis. These generally include blood tests to assess hormone levels, imaging, most often an ultrasound of the thyroid, and a thorough physical examination.

How are thyroid problems treated?

Treatment aims to bring thyroid hormone levels back to normal, with the strategy determined by the specific disorder. For hypothyroidism, the standard approach is thyroid hormone replacement. Managing hyperthyroidism may involve:

• Antithyroid medications to reduce hormone production
• Radioactive iodine therapy to limit hormone synthesis
• Beta blockers to alleviate symptoms such as palpitations
• Surgical removal of part or all of the thyroid

Medication for either condition can take several weeks to become fully effective, and follow-up blood tests are usually necessary to confirm that appropriate hormone levels have been reached.