Understanding Thyroid Health

Medically reviewed by: Kaya Merzlak, CRNP

The thyroid is a small, butterfly-shaped gland located at the front of the neck, but it has an outsized impact on overall health. It produces hormones that help regulate metabolism, energy levels, heart rate, body temperature, digestion, and even mood. When the thyroid is not functioning properly, many systems in the body can be affected.

According to the American Thyroid Association, thyroid disorders are common and often underdiagnosed because symptoms can be subtle and develop gradually.

What Does the Thyroid Do?

The thyroid produces two primary hormones — thyroxine (T4) and triiodothyronine (T3) — which travel through the bloodstream and influence how the body uses energy. The release of these hormones is regulated by thyroid-stimulating hormone (TSH), produced by the pituitary gland in the brain.

When this system is balanced, the body functions efficiently. When it’s disrupted, symptoms may appear throughout the body, not just in the neck or throat.

Common Thyroid Conditions

Hypothyroidism (Underactive Thyroid)

Hypothyroidism occurs when the thyroid does not produce enough hormone, causing the body’s systems to slow down. Symptoms often include fatigue, weight gain, cold intolerance, constipation, dry skin, hair thinning, and brain fog.

The most common cause of hypothyroidism in the United States is Hashimoto’s thyroiditis, an autoimmune condition in which the immune system mistakenly attacks the thyroid gland.

Diagnosis is typically made through blood tests measuring TSH and free T4 levels. Treatment usually involves thyroid hormone replacement therapy, which is safe and highly effective for most patients when properly monitored.

Hyperthyroidism (Overactive Thyroid)

Hyperthyroidism occurs when the thyroid produces too much hormone, speeding up the body’s metabolism. Symptoms may include unintended weight loss, rapid or irregular heartbeat, anxiety, heat intolerance, tremors, and changes in bowel habits.

The most common cause is Graves’ disease, another autoimmune condition. Clinical reviews published in journals such as the Journal of the American Medical Association note that hyperthyroidism can significantly impact cardiovascular and bone health if left untreated.

Treatment options vary depending on the cause and severity and may include medication, radioactive iodine therapy, or surgery.

Who Is at Risk for Thyroid Disease?

Thyroid disorders can affect anyone, but certain factors increase risk. According to the American Association of Clinical Endocrinology, higher-risk groups include:

Women
Individuals with a family history of thyroid disease
Those with other autoimmune conditions
People who have had radiation exposure to the head or neck

Because symptoms overlap with other conditions, such as stress, aging, or hormonal changes, thyroid dysfunction can go undetected without proper testing.

When Should You Consider Thyroid Testing?

You may want to talk to your healthcare provider about thyroid testing if you experience:

Persistent fatigue or unexplained weight changes
Sensitivity to cold or heat
Changes in heart rate
Mood changes or difficulty concentrating
Hair thinning or dry skin
Swelling or fullness in the neck

Single blood tests can provide valuable insight and help identify issues early when they are most manageable.

Living Well With Thyroid Conditions

With early detection, appropriate treatment, and regular monitoring, most people with thyroid disorders can live full, healthy lives. Management often involves medication adjustments over time and a proactive partnership with your healthcare provider.

Thyroid Awareness Month is a reminder that small symptoms can signal larger imbalances — and that preventive care plays a key role in long-term health.