An introduction to hypothyroidism and hyperthyroidism

Posted by Isabelle Eskew on 1/23/24 1:39 PM

January is Thyroid Awareness Month so we spoke with Dr. Scott McCusker, Ear, Nose and Throat specialist with Dignity Health Mercy Medical Group to learn about common thyroid diseases like hypothyroidism and hyperthyroidism. Dr. Scott McCusker

What are thyroid diseases?

“The thyroid is a small, butterfly-shaped gland in the front of your neck that makes thyroid hormones, which are our main regulator of metabolism,” says Dr. McCusker. “Thyroid hormones control the way your body uses energy, so they affect nearly every organ in your body. The two most common thyroid diseases are hypothyroidism and hyperthyroidism.”

Hypothyroidism is when your thyroid is not making enough thyroid hormones, or under activity, while hyperthyroidism is where your thyroid is making too much thyroid hormone, or over activity. 

Nearly 5 out of 100 Americans ages 12 and older have hypothyroidism, and about 1 out of 100 Americans ages 12 years and older have hyperthyroidism. Women and people over the age of 60 are more likely to develop a thyroid disease. 

What are common thyroid disease symptoms?

“We want the thyroid to secrete enough hormones to keep our metabolism normal. We don’t want it to create too little or too much,” says Dr. McCusker. “However, many of its symptoms are the same as those of other diseases, so be sure to discuss your concerns with your doctor or an endocrinologist.” 

Common Symptoms



  • Tiredness
  • Sensitivity to cold
  • Unintentional weight gain
  • Muscle weakness
  • Constipation
  • Slow heart rate
  • Decreased appetite
  • Low body temperature
  • Memory impairment
  • Depression
  • Dry skin, thinning hair
  • Racing heart, nervousness, anxiety and irritability
  • Sensitivity to heat
  • Unintentional weight loss
  • Muscle weakness
  • More frequent bowel movement
  • Tremors
  • Increased appetite
  • High body temperature
  • Mood swings

How are thyroid diseases diagnosed?
“A thyroid diagnosis cannot be given based on symptoms alone, says Dr. McCusker. “Your doctor may use several tests to confirm the diagnosis and find its cause including a physical exam, blood work, and imaging tests.”

How are thyroid diseases treated?
“While most thyroid diseases are chronic, or a lifelong medical condition, most patients can improve their quality of life with proper treatment,” says Dr. McCusker.

As thyroid disease varies from person to person, the approach to treatment also varies. 

With hypothyroidism, typically, medication is used to replace the hormones that your thyroid can no longer make. Your doctor will monitor your blood and adjust as needed until the proper dose has been determined. Once you start taking medication, it is likely that you will need to continue taking medication for life. 

With hyperthyroidism, there is no single treatment that works for everyone, as treatment will depend on what is causing your hyperthyroidism. Hyperthyroidism is often treated with medicine or surgery to remove part, or most of, the thyroid gland. Like hypothyroidism, once you start taking medication, it is likely that you will need to continue taking medication for life.

Key Takeaway
Thyroid disease symptoms can negatively impact your quality of life, but with the right treatment and plan of care, people can live a normal life.

If you suspect you may have a thyroid disease, schedule an appointment with your primary care physician. Our “Find a Doctor” tool can help you find a Dignity Health physician near you.


Meet Scott McCusker, MD

Topics: Mercy Medical Group, Ear Nose & Throat, Immunology, Dignity Health Mercy Medical Group, Thyroid

Welcome to the Dignity Health Medical Foundation news blog. Here we share health and wellness tips, the latest news from our medical groups, and more!

Recent Posts