Thyroid disorders are very common, affecting millions of people worldwide. The thyroid gland is a small, butterfly-shaped gland located at the base of the neck that produces thyroid hormones. These hormones help regulate metabolism, heart rate, body temperature, and many other important body functions. When the thyroid produces too much hormone, it causes hyperthyroidism or overactive thyroid. When it produces too little, it leads to hypothyroidism or underactive thyroid. Fortunately, most types of thyroid problems can be managed with the right treatment and monitoring.
What is the thyroid gland and what does it do?
The thyroid gland is an endocrine gland located in the front of the neck, just below the larynx (voice box). It is shaped like a butterfly, with two lobes connected by a narrow band of tissue called the thyroid isthmus. The thyroid gland secretes three hormones:
- Triiodothyronine (T3)
- Thyroxine (T4)
- Calcitonin
Thyroid hormones T3 and T4 help regulate:
- Metabolism – how quickly the body converts food and oxygen into energy
- Body temperature
- Heart rate
- Muscle strength
- Menstruation
- Weight
- Mood
Calcitonin helps regulate calcium levels in the blood by inhibiting osteoclasts, which break down bone. The thyroid gland is regulated by the hypothalamus and pituitary gland in the brain.
What are the most common thyroid disorders?
The most common thyroid disorders include:
Hypothyroidism
This is when the thyroid gland does not produce enough thyroid hormones. Common symptoms include fatigue, weight gain, sensitivity to cold, constipation, dry skin, depression, muscle aches, impaired memory, goiter (enlarged thyroid gland). Hashimoto’s thyroiditis is the most common cause of hypothyroidism.
Hyperthyroidism
This is when the thyroid gland produces too much thyroid hormone. Common symptoms include anxiety, irritability, unexplained weight loss, sweating, restlessness, tremors, rapid heartbeat, frequent bowel movements, fatigue despite sleeping well. Graves’ disease is the most common cause of hyperthyroidism.
Goiter
This is an abnormal enlargement of the thyroid gland, associated with hypothyroidism, hyperthyroidism, thyroid nodules, thyroid cancer, or iodine deficiency. Many people with a goiter have few or no symptoms.
Thyroid nodules
These are lumps that develop in the thyroid gland. Most are harmless but around 5% could be cancerous, so they require evaluation.
Thyroid cancer
This is fairly uncommon cancer that develops in the thyroid gland. It is usually treatable with surgery, radioactive iodine therapy, thyroid hormone treatment.
Thyroiditis
This is inflammation of the thyroid gland, often causing thyroid hormones to leak out into the bloodstream. Symptoms include pain in the thyroid, fever, temporary hyperthyroidism followed by hypothyroidism.
What causes thyroid problems?
There are several potential causes of thyroid disorders:
- Autoimmune disease – The immune system attacks the thyroid gland, causing inflammation and impaired function. Hashimoto’s thyroiditis and Graves’ disease are autoimmune disorders.
- Iodine deficiency – Consuming too little iodine can impair thyroid hormone production and cause hypothyroidism or goiter.
- Hyperthyroidism – Graves’ disease, toxic nodules or goiter, excess iodine intake, inflammation (thyroiditis) can lead to an overactive thyroid.
- Hypothyroidism – Hashimoto’s thyroiditis, thyroid surgery, radiation treatment, certain medications can reduce thyroid function.
- Thyroid nodules and cancer – The cause is often unknown but can include iodine deficiency, radiation exposure, family history.
- Pregnancy – Hormone changes or development of autoimmune thyroiditis after pregnancy can affect thyroid function.
- Pituitary gland malfunction – The pituitary gland produces TSH which controls thyroid function, so pituitary tumors or injury can disrupt thyroid hormone production.
How is hypothyroidism treated?
Hypothyroidism is treated with oral thyroid hormone replacement medication:
- Levothyroxine (Synthroid, Levoxyl, Unithroid, Tirosint) – This synthetic version of the T4 hormone brings thyroid hormone levels back to normal.
- Liothyronine (Cytomel) – This synthetic version of the T3 hormone may be added for people who don’t respond sufficiently to T4 alone.
Thyroid hormone replacement is usually required lifelong. The dose may need to be adjusted over time to keep thyroid levels optimized. Treatment is monitored through regular blood tests of TSH and thyroid hormone levels. With proper treatment, most symptoms of hypothyroidism can be reversed.
Treatment considerations
- Takes several weeks to notice improvement in symptoms
- Requires regular monitoring and potential dosage adjustments
- Best taken on an empty stomach 30-60 mins before food/drink (except water)
- Avoid taking with high fiber foods, calcium or iron supplements
- Notify doctor about any new medications that could interfere
How is hyperthyroidism treated?
There are several treatment options for hyperthyroidism:
Antithyroid medications
Methimazole (Tapazole) and propylthiouracil (PTU) block thyroid hormone production. They take several weeks to start improving symptoms and require close monitoring of thyroid levels. Side effects can include rash, itching, upset stomach.
Radioactive iodine
Taking radioactive iodine by mouth gradually destroys overactive thyroid cells. More than 80% of people with Graves’ disease treated with RAI develop permanent hypothyroidism and require thyroid hormone replacement. RAI may not be suitable for people with eye disease related to Graves’.
Surgery
Removing part or all of the thyroid gland is an option if antithyroid meds or RAI are unsuitable or ineffective. Risks include damage to vocal cords and parathyroid glands. Lifelong thyroid hormone replacement is required after complete thyroidectomy.
Beta blockers
Medications like propranolol help relieve hyperthyroidism symptoms like rapid heart rate, tremor, anxiety while waiting for other treatments to take effect.
Are thyroid problems permanent?
The course of thyroid disorders can vary:
- Untreated hypothyroidism is lifelong but very manageable with thyroid hormone replacement.
- Hyperthyroidism may be temporary (thyroiditis, postpartum thyroiditis) or permanent (Graves’ disease, toxic nodules).
- Goiter may resolve when underlying cause is corrected (like iodine repletion) or require treatment if large.
- Thyroid nodules are usually permanent but can be monitored or treated if necessary.
- Thyroid cancer is usually treated successfully with high long-term cure rates, but lifetime monitoring is required.
For autoimmune thyroid disorders like Hashimoto’s and Graves’ disease, periodic fluctuations in thyroid function are common even with treatment. Close follow-up and medication adjustments are often needed to keep thyroid levels optimized.
Can thyroid disorders be prevented?
It’s difficult to prevent autoimmune thyroid problems, but the following healthy habits can help lower risk:
- Get enough iodine – Use iodized salt, seafood, eggs, dairy products.
- Maintain healthy weight – Obesity increases risk of thyroid disorders.
- Reduce stress – Chronic stress impairs immune regulation and can worsen autoimmune thyroiditis.
- Avoid smoking and excess alcohol – Both damage the thyroid gland over time.
- Treat other autoimmune conditions – Having one autoimmune disease increases the risk of developing others.
Early diagnosis, effective treatment, and careful monitoring can help prevent hypothyroidism or hyperthyroidism from causing further thyroid gland damage and other complications.
What is the prognosis for thyroid disorders?
With proper treatment, most people with thyroid problems can expect an excellent prognosis and normal life expectancy. However, complications can arise if thyroid disorders go untreated for prolonged periods:
- Severe untreated hypothyroidism can lead to myxedema coma, a rare but life-threatening condition.
- Untreated hyperthyroidism can cause atrial fibrillation, heart failure, osteoporosis, and thyroid storm.
- Enlarged goiters may impair breathing and swallowing if left untreated.
- A small percentage of thyroid nodules may harbor cancer, which requires treatment.
That’s why it’s important to seek medical care for persistent thyroid-related symptoms, maintain any recommended treatment and follow-up monitoring, and discuss symptoms at each visit. With timely diagnosis and therapy, most people with thyroid problems can avoid complications and feel their best.
Summary
Thyroid disorders like hypothyroidism and hyperthyroidism are common, but modern treatments allow most people to manage their thyroid problems effectively. Lifelong thyroid hormone replacement is often required for hypothyroidism. Hyperthyroidism may be temporary or require methods like antithyroid medications, radioactive iodine, or surgery for lasting control. While thyroid conditions are usually permanent and require ongoing care, they can typically be well-controlled with the right treatment and monitoring. Working closely with an endocrinologist or other thyroid care specialist is advised to achieve optimal health and prognosis.
