Thyroid Troubles: The Tiny Gland That Makes a Big Impact

Have you ever wondered how your body is able to maintain its energy, your heart beating steadily, or even how you stay warm on a chilly day? It's likely these aren't things you think about on a daily basis, so I bet you didn't know that your thyroid is behind all of that—and more. This small, butterfly-shaped gland found at the base of your neck plays a major role in keeping your body running smoothly by producing hormones that regulate energy, metabolism, mood, and more. When something's off with the thyroid, it can cause a whole range of symptoms that can greatly affect your daily life in many surprising ways. This blog post aims to share several thyroid pathologies, including the causes, effects, treatment, and more.

Hyperthyroidism: Too Much of a Good Thing

If you ever feel like your body's running overdrive—sweating for no reason, losing weight without trying, or feeling your heart race when you're just sitting still—it's possible your thyroid might be working a little too hard. That's what happens in patients with hyperthyroidism, when this small but mighty gland pumps out more hormones than your body requires.

What causes hyperthyroidism?

Like many diseases, there are multiple common reasons as to the cause of a hyperactive thyroid

• Graves' Disease – An autoimmune condition (type II hypersensitivity) where antibodies stimulate the TSH (thyroid-stimulating hormone) receptor, causing excess thyroid hormone production.  This is the most common cause, especially in the younger population.

• Goitre – Endemic or sporadic iodine deficiency, causing enlargement of the thyroid gland, which can often lead to nodules that become autonomous and produce excess thyroid hormones. This is more common in older adults.

• Toxic Adenoma – A single thyroid nodule that independently produces excess thyroid hormone due to mutations in the TSH receptor.

How is it diagnosed?

Doctors will usually begin with a blood test, as patients with hyperthyroidism will often have:

• Low TSH levels

• High free T4 and total T3 levels (thyroid hormones)

  
  

These signs are indicative of a hyperactive thyroid and may be causing thyrotoxicosis (aka, hormone overload). Radioactive iodine scans can also be useful in determining etiology.

What are the symptoms?

Symptoms can always vary from person to person, but common symptoms include:

• Sweating

• Weight Loss

• Hypermotility of GI Tract (Malabsorption & Diarrhea)

• Cardiac effects (Palpitations & Tachycardia)

• Neuromuscular Effects (tremor, nervousness & proximal muscle weakness)

• Ocular Effects (upper lid retraction/wide-eye stare)

How can it be treated?

Thankfully, hyperthyroidism can be treated via several ways:

• Antithyroid Drugs (ATDs): These drugs block thyroid hormone production and may help suppress the immune response, especially in Graves disease.

• Radioactive Iodine (RAI): This treatment destroys thyroid cells using iodine-131, reducing hormone production but may temporarily increase thyroid hormone levels.

Hypothyroidism: Slowing to A Crawl

Unlike the buzz of hyperthyroidism, hypothyroidism is more of a slow fade. Your thyroid isn’t making enough hormone to keep things running smoothly, and over time, everything from your metabolism to your mood can take a hit. It’s one of those conditions that can be easy to overlook—or blame on life being busy—until it starts affecting nearly every part of your day.

Types of hypothyroidism: How it happens?

It is important to note that not all hypothyroidism is the same. In fact, there are actually several different ways your thyroid can lose its function. Here is a quick breakdown of the most common types:

1. Primary Hypothyroidism – The most common type, often caused by thyroid-specific factors like Hashimoto’s disease or surgery, resulting in reduced thyroid hormone production.

2. Secondary Hypothyroidism – This type isn't actually a problem with the thyroid, but rather caused by an underactive pituitary gland, leading to low TSH (thyroid-stimulating hormone) and reduced thyroid hormone release.

3. Tertiary Hypothyroidism – Think of this as one step higher up the chain. In this case, the hypothalamus—a different part of the brain—doesn't produce enough TRH (thyrotropin-releasing hormone), which means the pituitary gland doesn't release TSH, and the thyroid never gets activated.

4. Subclinical Hypothyroidism – This one is more of a special case where your thyroid hormone levels might still be in the normal range, but your TSH is slightly elevated. It usually resolves itself within a few months, but definitely worth keeping an eye on.

Signs and Symptoms

When your thyroid isn’t pulling its weight, it can affect almost every part of your body—and the symptoms can be surprisingly subtle at first. Here are some of the most common signs people experience when their thyroid starts slowing down:

• Weight gain

• Fatigue

• Depression

• Low cold tolerance

• Joint and muscle pain

• Dry skin and/or hair

• Slowed heart rate

• Heavy or Irregular menstrual periods or fertility problems

Methods of diagnosis

If you or your doctor suspect something’s up with your thyroid, the next step is figuring out what’s really going on. Diagnosis usually involves a mix of:

• Physical exam and medical history - Your doctor will likely start by asking about your symptoms, medical history, and do a quick physical exam (like checking for swelling in the neck).

• Thyroid blood tests - This is very important, as they will look at your TSH and thyroid hormone levels (T3 and T4) to see if your thyroid is underperforming.

• Thyroid imaging tests - Not always necessary but in some cases, an ultrasound or other scans might be used to check for nodules or structural changes in your thyroid.

How is it treated?

The primary treatment for hypothyroidism is usually levothyroxine—a medication that essentially replaces the thyroid hormones your body isn't making enough of. It's like giving your body a little extra help to keep things running smoothly. It is a straightforward treatment, where your doctor will likely monitor your thyroid hormone levels to ensure that the dose is correct, with the hopes of returning thyroid hormone levels back to normal.

Goiters: When the Thyroid Grows

What is a Goiter?

Goiter is simply an abnormal enlargement of the thyroid gland, located at the base of your neck. It’s a sign that something is affecting your thyroid – though not always linked to over or underactive thyroid hormone levels. It is essentially a red flag that something is off with your thyroid, but there could be various reasons behind it.

Types and causes of goiters

Goiters can develop for several reasons, including:

• Iodine deficiency – Your thyroid needs iodine to make hormones, and when you don’t get enough, the thyroid might enlarge. This is the most common cause worldwide.

• Autoimmune diseases – Conditions like Graves' disease (overactive) or Hashimoto’s thyroiditis (underactive) can mess with thyroid function, causing swelling.

• Thyroid Cancer – In rare cases, a goiter can be caused by cancerous growths within the thyroid gland.

• Thyroid nodules – These growths can develop inside your thyroid, causing it to enlarge.

• Pregnancy – Hormonal changes during pregnancy can also lead to a temporary goiter.

Symptoms: What to look for

Physical Symptoms

• Visible swelling at the base of neck

• Tight feeling in the throat

• Hoarseness of voice change

• Difficulty swallowing

• Breathing difficulties 

Hormonal symptoms

When associated with hypothyroidism

• Fatigue, weight gain, cold intolerance, depression, dry skin, constipation, slowed heart rate

When associated with hyperthyroidism

• Nervousness or irritability, weight loss, heat intolerance, tremors, increased sweating, rapid/irregular heartbeat 

Diagnosis: How do you know it's a goiter?

If you're noticing symptoms, your doctor will likely start with:

• Physical exams – Doctors can very easily feel around your neck to check for swelling and nodules, specifically assessing neck size and consistency

• Blood tests – To check your TSH, T3, and T4 levels. These can help figure out if your thyroid is overactive or underactive.

• Thyroid ultrasound – This helps determine the size and structure of the goiter.

• Radioactive iodine uptake scan – This can show how active the thyroid is and help identify conditions like Graves' disease or toxic nodular goiter.

• Fine needle aspiration – If there’s a suspicious or large nodule, this biopsy can rule out cancer.

Treatments: How to shrink the unwanted swelling

• Iodine supplementation – Rare in countries with iodized salt, but if iodine deficiency is the cause, this can help shrink the goiter.

• Thyroid hormone therapy – If you’ve got a goiter from hypothyroidism, levothyroxine can help normalize hormone levels and shrink the gland by reducing TSH stimulation.

• Anti-thyroid medications – Drugs like methimazole or propylthiouracil can help shrink a goiter caused by hyperthyroidism by reducing thyroid hormone production.

• Radioactive iodine therapy – This helps shrink overactive thyroid tissue and is especially useful for toxic multinodular goiters.

Thyroid Cancers: When Cells Go Rogue

Types of thyroid cancer

There are different types of thyroid cancer, each with its own behavior and outlook:

• Papillary (84% of cases) – The most common type. It starts in the hormone-producing cells of the thyroid and is typically slow-growing. It’s often curable, especially when caught early.

• Follicular (4% of cases) and Oncocytic (2% of cases) – These are less aggressive types of cancer that tend to behave fairly normally, with generally favorable outcomes.

• Medullary (4% of cases) – This one arises from parafollicular C cells in the thyroid. It’s often hereditary, occurring in about 25% of cases, and may run in families.

• Poorly Differentiated/Anaplastic (6% of cases) – These types are aggressive and tend to arise from less aggressive thyroid cancers. They often have a poor response to treatment and require more intensive management.

Symptoms to watch out for

Most cases of thyroid cancer don’t show symptoms in the early stages. In fact, many people find out about it incidentally during a routine physical exam or imaging for something else. But, as the cancer progresses, some signs to watch for include:

• Lumps or swelling in the neck (often the first noticeable sign)

• Difficulty swallowing (known as dysphagia)3

• Hoarseness or changes in your voice

• A feeling of having a lump in your throat, even if there’s nothing obvious

Diagnostic Tools

Treatments

Why This Matters

As pathology students, we created this blog post to shine a light on thyroid disorders. These are conditions that affect millions worldwide but often go undiagnosed. Whether you’re a student, a curious reader, or someone dealing with symptoms, understanding the thyroid is one small step toward taking control of your health.

Let us know what you learned, and feel free to share this post to help spread awareness. Your thyroid may be small, but the impact it has is anything but.