Why You Could Have Thyroid Disease and Not Know It
By Sucharitha Kankanala, MD, Virtua Endocrinologist
Thyroid disease isn’t a health topic that often makes headlines. According to American Thyroid Association, it is estimated that 20 million Americans have hormonal imbalances from thyroid disorders, and up to 60 percent of those with thyroid disease go undiagnosed. There are many effective treatments for thyroid problems, but getting to a diagnosis is sometimes a bigger challenge.
Symptoms of thyroid disorders can appear like signs of normal aging or other conditions. These include fatigue, memory lapses, irritability, sleep problems, thinning hair, constipation and/or weight gain.
If you have these symptoms, your primary care doctor can order a simple blood test to measure your thyroid levels.
What Does the Thyroid Do?
The thyroid is a tiny neck gland that plays a significant role in the body. Simply, the thyroid gland takes iodine found in many foods and converts it into thyroid hormones, called T3 and T4. Every human cell depends on thyroid hormones to regulate metabolism (the conversion of oxygen and calories to energy). Two other glands, the pituitary and the hypothalamus, use their own hormones (TSH and TRH) to continually communicate with the thyroid—measuring and stimulating the release or decrease of T3 and T4 hormones, depending on the body’s needs.
Symptoms and Causes of Hypo- and Hyperthyroid Disease
Hypothyroidism, or an underactive thyroid gland, is the most common thyroid condition and slows down normal body function. According to the American Thyroid Association, common causes of hypothyroidism include:
- Autoimmune disease
- Surgical removal of the thyroid
- Radiation treatment
- Congenital hypothyroidism (hypothyroid present at birth)
- Inflammation of the thyroid (thyroiditis)
- Medicines that prevent the thyroid from making hormones normally
- Too much or too little iodine in your diet
- Damage to the pituitary gland
- Rare disorders that can impair thyroid function
In its early stages, hypothyroid symptoms may not be obvious. Gradually, more symptoms appear including fatigue or drowsiness, weight gain or fluid retention, dry hair, skin or nails, constipation, or sore muscles.
Hyperthyroidism develops when the body produces, or is exposed to, high levels of thyroid hormone. This disorder affects women 5 to 10 times more often than men. As with hypothyroid, the symptoms may not initially appear to be thyroid-related.
Hyperthyroid symptoms include a fast heart rate (palpitations or heart racing), trembling hands, unexplained weight loss, anxiety or irritability, hair loss, diarrhea, or frequent perspiration.
Some causes of hyperthyroidism include:
- Graves’ disease (disease that causes the thyroid to secrete too much thyroid hormone)
- One or more nodules in the thyroid
- A viral infection that affects normal function of the thyroid gland
- Overmedication with a thyroid hormone
Having thyroid conditions in your family, raises your risk but is only one of the risk factors. Family history of autoimmune diseases such as Graves’s disease, Hashimoto’s disease, lupus, or rheumatoid arthritis also raises your risk.
What to Know About Testing
Your primary care doctor can order blood tests to check your TSH and other thyroid hormone levels during routine physicals. Your doctor may refer you to an endocrinologist if your symptoms are difficult to diagnose, or if your symptoms are hard to manage. Endocrinologists are doctors who specialize in managing thyroid disease and other glandular (metabolic) disorders.
Acceptable levels or “reference ranges” of TSH can vary from lab to lab. Currently, most labs in the U.S. have an official “normal” reference range for TSH levels of .4 to 4.5. TSH is a screening test; further testing may be needed if symptoms are concerning for thyroid disorder. In the case of autoimmune thyroid disease, TSH levels may be normal; a thyroid auto-antibodies test detects autoimmune thyroiditis.
Thyroid ultrasound and imaging scans look at gland size and nodules. And, radioactive nuclear imaging shows hot or cold spots in the glands and increased or decreased activity.
Arm yourself with as much information as possible to help your doctors determine if your thyroid function is impaired. Treatments are widely available and can help you get back to feeling better fairly quickly.
Updated January 8, 2020