The Top Signs Your Thyroid is Overactive or Underactive

The thyroid is a small hormone-producing gland in your neck that’s responsible for regulating metabolism and body functions, including your heart rate and energy levels. With its ability to influence nearly all body systems, you would think a dysfunctional thyroid would make itself known. However, according to the American Thyroid Association, up to 60 percent of people suffering from a thyroid condition have no idea!

An estimated 20 million Americans have some form of thyroid disease, the majority of whom are women, who are five to eight times more likely than men to experience thyroid issues.

Some additional risk factors for thyroid issues include:

  • Family and personal history of cancers or thyroid disorders
  • Certain medical conditions
  • Medications
  • Age

So how can you tell if your thyroid isn’t doing its job? Let’s dig into some of the most common thyroid conditions, symptoms to look for, and possible treatments.

Thyroid Conditions

Thyroid disorders are often categorized as hyperthyroidism or hypothyroidism. These names describe the abnormal levels of thyroid hormone, specifically T3 and T4, produced with these conditions.

This naming process can be confusing because lab providers use Thyroid Stimulating Hormone (TSH), a pituitary hormone involved in thyroid hormone production, to initially screen for thyroid disorders, and TSH can be elevated in hypothyroidism or low in hyperthyroidism. More commonly, and to spare confusion, you can think of hyperthyroidism as an overactive thyroid and hypothyroidism as an underactive thyroid.

Here are a few common thyroid conditions worth knowing about.

Grave’s disease

This hereditary, autoimmune form of hyperthyroidism is often accompanied by changes in the eyes and skin and a rapid heart rate.

Hashimoto’s disease

This autoimmune hypothyroidism is also inherited and the damage to the thyroid ultimately results in low thyroid hormone production.

The Top Signs Your Thyroid is Overactive or Underactive


This often self-limiting condition results in painful swelling or inflammation of the thyroid gland. This condition is considered reactive, as it is triggered by pregnancy and post-partum, infections, radiation, medications, or autoimmune disorders. With thyroiditis, thyroid hormone levels, specifically T3 and T4, may be high initially, drop low, and ultimately normalize over time. Over the course of this condition, you may present with symptoms of both hyperthyroidism and hypothyroidism.


This swelling of the neck results from a painless, enlarged thyroid. It can be a smooth, diffusely enlarged thyroid gland, or it may feel bumpy if nodules (solid or fluid-filled lumps) grow on the gland. Iodine deficiency can cause goiters. However, most people eat plenty of iodized salt today, making iodine deficiency and goiters less common.  A goiter is often referred to as a toxic goiter or a non-toxic goiter, depending on the thyroid hormone levels in the blood.

Thyroid nodules

As mentioned, these masses can grow on the thyroid gland. Your provider may palpate them during an exam or find them incidentally while doing other diagnostic imaging. These can be benign, or they may indicate thyroid cancer.

Subclinical hypothyroidism and hyperthyroidism

When you have these two conditions, your lab results are abnormal, but you have no symptoms.

Common Symptoms of Thyroid Problems

To determine if you may have a thyroid disorder, look for these common symptoms of an overactive and underactive thyroid.

Overactive thyroid

With this category of thyroid conditions, think of your body functions and processes as speeding up, which may result in the following symptoms. An overactive thyroid is most prevalent in people between 20 to 40 years old.

  • Unexplained weight loss
  • Menstrual changes, including irregular cycles or missed periods
  • Anxiety or irritability
  • A rapid heart rate at rest of more than 100 beats per minute
  • Vision problems, eye irritation, or bulging eyes
  • Difficulty sleeping
  • Heat intolerance or feeling warm
  • Muscle weakness
  • Difficulty focusing
  • Tremors

Underactive thyroid

Due to shrinking of the thyroid and its functional failure that naturally occurs over time, increasing age is a risk factor for underactive thyroid conditions. It’s most common in people over the age of 60. With this category of thyroid conditions, imagine your body systems are all slowing down, which may result in the following symptoms.

  • Hair loss or a change in the texture of the hair to dry and coarse
  • Dry skin
  • Menstrual changes, especially heavier and more frequent cycles
  • Weight gain or difficulty losing weight despite consistent effort
  • Constipation
  • Fatigue or lack of energy
  • Hoarse voice
  • Facial swelling or puffiness
  • Always feeling cold
  • Depression
  • Slow heart rate at rest of under 60 beats per minute
  • Muscle weakness or cramping
  • Memory loss

The following severe thyroid symptoms are rarer but warrant an urgent evaluation or even a visit to the emergency room.

  • Choking or difficulty swallowing
  • Enlarged or noticeable swelling of your neck
  • Palpitations or irregular heart rhythm, especially if associated with chest pain
  • Sudden vision loss
  • Sustained heart rate of more than 110 beats per minute at rest
  • Myxedema, which causes severe swelling of the face and extremities and thickening and discoloration of the affected skin
  • Unintentional weight gain or loss of more than 10 pounds in one month

Treating Thyroid Conditions

What’s next? If you’re experiencing any of the symptoms above, make an appointment with your primary care provider to run some basic blood work for testing. Avoid biotin supplements within twelve hours of any lab work as these can give false thyroid lab results.

Depending on your symptoms and lab results, your medical team may recommend one of the following courses of action.

  • If your lab values are normal, they may advise a “watch and wait” approach.
  • If the lab work is unclear, they may order additional tests, which could include T3 and T4 values and thyroid antibodies.
  • If they suspect a nodule, goiter, or thyroiditis, they may perform diagnostic imaging and a needle biopsy.
  • They may refer you to an endocrinologist, who specializes in thyroid disorders.
  • They may suggest radioactive iodine therapy for enlarged thyroids or overactive thyroid disorders. This is a chemical radiation treatment delivered in an oral capsule. You take one pill that targets and destroys thyroid cells, therefore limiting their production of excess thyroid hormones. Radiation therapy sounds scary, but this is generally well-tolerated and can be taken at home.
  • They may prescribe medications, which can include the following:
    • Synthetic thyroid hormone for hypothyroidism: levothyroxine or liothyronine sodium. (Desiccated thyroid extract from pig thyroids is no longer considered a first-line therapy and is not FDA-approved.)
    • Beta-blockers for symptoms of hyperthyroidism
    • Prednisone for thyroiditis
  • They may advise surgical intervention for large or cancerous nodules. Depending on the extent of disease, your medical team may recommend a partial or total thyroidectomy.

Can You Prevent Thyroid Conditions?

There’s no sure way to prevent thyroid disorders, but you can improve your chances of early detection with the following strategies.

  • Visit your health provider for routine lab work and get your TSH levels measured.
  • Know your risk factors, including family history, age, medications, and medical conditions commonly associated with certain thyroid conditions.
  • Get enough selenium. Diets low in this nutrient have been linked to thyroid conditions. It’s safe to ingest between 55 to 400 mcg, and good sources include nuts, seafood, beef, turkey, chicken, whole-wheat bread, beans, lentils, and fortified cereals.
  • If you’re on a sodium (salt) restricted diet, ask your provider about alternative iodine supplementation.


Thyroid disorders are common, yet they often go undetected. If you notice some of the symptoms above and believe you may have a thyroid disorder, reach out to your medical provider for an appointment.

By Caitlin Pratz

Caitlin Pratz is a Registered Nurse who has been practicing for 11 years. Her diverse professional experience includes hospital, clinic, and school-based nursing. Outside of work and writing, she enjoys spending time with her husband and two dogs in her home state of Texas.