What Causes Thyroids: Understanding Thyroid Problems in Adults

Understanding the Main Causes of Thyroid Problems in Adults

The thyroid gland, a small butterfly-shaped organ in your neck, plays a central role in your overall health. It produces hormones that regulate metabolism, energy levels, body temperature and even mood. If the thyroid malfunctions, it can affect almost every system in the body.

Thyroid disorders are increasingly common. Research indicates that over 42 million people in India are affected by various thyroid conditions. If you’ve been wondering what causes thyroid problems, you are not alone. Whether it’s hypothyroidism (an underactive thyroid) or hyperthyroidism (an overactive thyroid), these conditions can significantly impact your quality of life.

The good news is that understanding the causes of thyroid problems is an important step toward prevention and effective management. In this article, we break down what causes thyroid dysfunction so you can recognise risk factors and make informed decisions about your health.

What Are the Main Autoimmune Causes of Thyroid Problems?

Autoimmune diseases are a leading cause of thyroid dysfunction in adults. Normally, your immune system protects you from harmful elements like bacteria and viruses. However, it can sometimes attack the body’s own tissues; a condition known as an autoimmune disease.

There are two main autoimmune conditions related to thyroid problems:

• Hashimoto's Thyroiditis

  Hashimoto’s thyroiditis is the most common cause of hypothyroidism worldwide. In this condition, the immune system gradually destroys thyroid tissue, reducing the gland’s ability to produce hormones. Symptoms often develop slowly over months or years. Women are seven to ten times more likely to develop Hashimoto’s than men.

• Graves' Disease

  Graves’ disease causes the thyroid to produce excessive hormones, leading to hyperthyroidism. The immune system produces antibodies that may trick the thyroid into overworking. Symptoms include rapid heartbeat, weight loss, anxiety, trembling hands and bulging eyes. Graves’ disease is more common in women and typically develops between ages 20 and 50.

Can Medications and Medical Treatments Cause Thyroid Problems?

Yes, several commonly prescribed medications and medical treatments can interfere with thyroid function, potentially causing hypothyroidism or hyperthyroidism.

• Lithium: Lithium, used to treat bipolar disorder, is well-known for causing hypothyroidism. It interferes with the production and release of thyroid hormones, and up to 20% of people taking lithium may develop thyroid problems.
• Amiodarone: Amiodarone, a medication for irregular heartbeats, contains high amounts of iodine and can cause both hypothyroidism and hyperthyroidism. Its effect on the thyroid may persist for months due to its long half-life in the body.
• Interferon Alpha and Interleukin-2: These medications, used to treat certain cancers and hepatitis C, can trigger autoimmune thyroid disease in susceptible individuals. About 15% of patients receiving these treatments may develop thyroid dysfunction.
• Radiation Therapy: Radiation therapy to the head, neck or chest can damage the thyroid gland. Cancer survivors who have received radiation in these areas often require lifelong thyroid monitoring.

What Role Does Genetics Play in Thyroid Disease?

Genetics has a significant influence on thyroid health, with family history being one of the strongest risk factors for developing thyroid disorders. If your mother, father or siblings have thyroid disease, your risk of developing thyroid problems increases substantially. Studies indicate that heredity accounts for approximately 60-80% of the risk for autoimmune thyroid disease.

Several genes can increase susceptibility to thyroid disorders, including those related to immune system function and genes directly involved in thyroid hormone production and regulation. The genetic link is especially strong for Graves’ disease and Hashimoto’s thyroiditis. People with a family history of these conditions are much more likely to develop them than those without a similar family history.

How Do Stress and Lifestyle Factors Affect Thyroid Function?

While chronic stress and poor lifestyle choices may not directly cause thyroid disease, they can trigger dysfunction in vulnerable individuals or worsen existing conditions.

There is a complex relationship between stress and thyroid health. Prolonged stress increases cortisol, the stress hormone, which can suppress thyroid function.

Sleep deprivation also affects thyroid function. Thyroid hormone production follows a daily rhythm, with peak levels occurring during sleep. Chronic sleep problems can disrupt this rhythm and contribute to imbalances.

Diet and exercise play important roles as well. Extreme calorie restriction or excessive exercise may suppress thyroid function as the body tries to conserve energy. Maintaining a healthy body weight through a balanced diet and moderate exercise supports optimal thyroid function.

Additionally, exposure to environmental toxins, particularly endocrine-disrupting chemicals found in pesticides, plastics and certain personal care products, has been linked to thyroid problems.

Does Pregnancy Affect Thyroid Health?

Yes, pregnancy has a significant impact on thyroid function. Thyroid problems may develop during or after pregnancy in women with no previous history of thyroid disease. The thyroid works harder during pregnancy to support both the mother and the developing baby. Your body’s iodine requirement increases substantially, and it produces approximately 50% more thyroid hormone.

Postpartum thyroiditis affects around 5-10% of women within the first year after delivery. This condition generally involves a temporary period of hyperthyroidism followed by hypothyroidism. Many women recover completely, but around 20–30% develop permanent hypothyroidism that requires lifelong treatment.

Preexisting thyroid conditions may also change during pregnancy, which is why regular thyroid monitoring is essential. Untreated thyroid problems during pregnancy can have serious consequences, including miscarriage, premature birth, low birth weight and developmental problems in the baby.

What Other Medical Conditions Can Trigger Thyroid Problems?

Several other health conditions are associated with an increased risk of thyroid dysfunction. For instance, type 1 diabetes frequently co-exists with autoimmune thyroid disease. Celiac disease, an autoimmune condition triggered by gluten, also has strong links to thyroid problems.

Additionally, polycystic ovary syndrome (PCOS), which is common in Indian women, has been linked to a higher rate of thyroid disorders, particularly hypothyroidism. Turner syndrome, a genetic condition affecting females, carries a high risk of thyroid problems. Similarly, pituitary gland disorders can cause thyroid dysfunction, as problems with the pituitary may lead to secondary thyroid disorders.

Conclusion

Understanding what causes thyroid problems empowers you to take control of your health. While autoimmune conditions like Hashimoto’s thyroiditis and Graves’ disease are common culprits, factors such as iodine deficiency, genetics, medications and stress also play a role.

Being aware of your risk factors, including family history, other autoimmune conditions or symptoms like unexplained weight changes, fatigue or mood swings, allows you to act early. A simple thyroid blood test can detect issues when they are most treatable.

With timely diagnosis, proper treatment and healthy lifestyle practices, thyroid disorders are highly manageable. Most people with thyroid problems can lead normal, active lives and protect their long-term health.