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Thyroid Tests (Thyroid Screening)

Thyroid disease occurs when the thyroid gland, part of the endocrine system, malfunctions either because it produces too much (hyperthyroidism) or too little (hypothyroidism) thyroid hormone.

If left untreated, health problems range from issues with metabolism, cardiac and nervous system function, sleep disturbances, changes in mood, increased irritability, constipation, fatigue, and muscle weakness. Thyroid tests help identify if this is a problem.

Schedule this Screening
*Screening availability may be limited by location.

About Thyroid Disease

The thyroid is a butterfly shaped organ at the base of the neck, in the front. It has a dramatic effect on a wide variety of your bodily functions. It is the largest endocrine gland in your body, and it produces two hormones: T3 and T4. They control the rate at which your body burns energy and responds to stress hormones. Because the thyroid plays such an important role in understanding your overall health, Life Line Screening offers thyroid screening through a thyroid panel test (blood tests).

Thyroid tests include the blood tests mentioned here to measure thyroid hormones, but your physician may also order ultrasound or a radioactive iodine reuptake test.2

Thyroid function screening looks at two ways your thyroid can malfunction: Hyperthyroidism (when too much thyroid hormone is produced in the body) and Hypothyroidism (when not enough thyroid hormone is produced). Here are just some of the signs that there is something wrong with your thyroid:

You’re always tired

Chronic fatigue could be a sign of either hypothyroidism or hyperthyroidism. If you have hypothyroidism, you feel tired even after a full night’s sleep because there isn’t enough thyroid hormone in your bloodstream, so your muscles aren’t getting a signal to get going in the morning. If you have hyperthyroidism, you probably can’t sleep well at night, causing you to feel tired in the morning. Chronic fatigue can be attributed to many things, which is why getting a thyroid hormone test is important – to either rule thyroid problems out as a cause, or point to a possible problem.

Your mood has changed

Feeling unusually depressed or sad might mean that you have hypothyroidism. The lack of thyroid hormone has an impact on your brain’s production of serotonin, the “feel good” hormone in the brain. If you feel anxious, jittery, or wired, you might have hyperthyroidism because your thyroid is making too much of its hormone. Your brain is flooded with messages, your metabolism speeds up, and your whole body goes into overdrive. If you notice either of these changes in your mood, you should get a thyroid hormone test.

You’re always too hot/too cold

If you feel cold all the time or that you have the chills, you may have hypothyroidism. Your system slows down because of an underactive thyroid, and that means less energy is being burned by your cells. Less energy means less heat. If you are always warm or sweating profusely, you may have hyperthyroidism and should have a thyroid disease screening test performed as soon as possible. That’s because your cells are in overdrive, producing too much heat. A thyroid test can help identify if the thyroid is contributing to this symptom.

Hypothyrodism is common in patients over the age of 60 and increases with age.1 One cause is called Hashimoto’s Disease, which affects more women than men, and is most common between the ages of 40-60. It is an autoimmune disease in which the immune system makes antibodies that attack the thyroid gland. The risk of developing Hashimoto’s Disease goes up if you have other autoimmune diseases such as rheumatoid arthritis, celiac disease, or Type I Diabetes. Hashimoto’s Disease is diagnosed through a thyroid function screening, measuring the hormones, and an antibody test.2

If not treated, this condition can cause infertility, miscarriage, birth defects, high cholesterol, or in very rare cases, heart failure, seizures, coma and death. A simple thyroid test can pick up the warning signs before anything bad happens. Hashimoto’s Disease can be treated with a daily dose of thyroid hormone called levothyroxine.3

Hyperthyroidism, or too much thyroid hormone, is also called Graves’ Disease and can speed up your heart, make you feel heart palpations and cause you to feel nervous or anxious. This puts a strain on your heart and can have long-term implications for your overall cardiovascular health, which is why a thyroid test can be so beneficial to finding a potential problem early.4

Thyroid Disease Screening Details

A simple finger-stick blood test, a thyroid screening test, is used to measure thyroid-stimulating hormone (TSH) levels, the key indicator for how well the thyroid gland is functioning. No fasting is required. TSH hormone levels are reported in mIU/L, which is milli-international units per liter of blood. The normal range for TSH is .50-4.59 mIU/L; below normal indicates a possibly overactive thyroid, and above the normal range indicates a potentially underactive thyroid. If your results are outside of the normal range, you should bring this to the attention of your personal physician.

Thyroid Stimulating Hormone (TSH), produced by the pituitary gland in the brain, plays a key role in regulating thyroid hormone production. An abnormal TSH level can cause the thyroid gland to malfunction and lead to a variety of health issues. This is why a thyroid test becomes important.

Warning Signs

Some symptoms of hyperthyroidism include:

  • Nervousness or irritability
  • Heat intolerance
  • Weight loss
  • Frequent bowel movements
  • Fatigue or muscle weakness
  • Trouble sleeping
  • Goiter
  • Mood swings
  • Rapid and irregular heartbeat
  • Hand tremors

Some symptoms of hypothyroidism include:

  • Weight gain
  • Sleepiness
  • Dry skin/brittle fingernails
  • Constipation
  • Fatigue
  • Memory loss
  • Decrease in cognitive function

Risk Factors for Thyroid Disease

  • Women have a 2 to 10 times greater risk for a thyroid disorder
  • Adults over 60 years of age
  • Women who have been pregnant or have delivered a baby within the last six months
  • Those with a family history of thyroid disease
  • Those who have been treated for a thyroid problem
  • Those who have had neck surgery or radiation
  • Anyone with pernicious anemia (a vitamin B12 deficiency)
  • Those with type 1 diabetes
  • Those with primary adrenal insufficiency

Who is the Thyroid test for?

Thyroid screening is important for a variety of groups. Women have a 2 to 10 times greater chance of developing a thyroid disorder than men. Adults who are over 60 as well as women who have been pregnant or have delivered a baby within the last six months are also at higher risk. Other at-risk groups include those with a family history of thyroid disease, those who have been treated for a thyroid problem, those who have had neck surgery or radiation, as well as anyone with a vitamin B12 deficiency known as pernicious anemia, type 1 diabetes, or primary adrenal insufficiency.

It’s estimated that more than 20 million Americans have some form of thyroid disease. If you notice any of these signs or symptoms, then it’s time for a thyroid function screening test. The earlier you detect the problem, the faster you and your doctor can determine if treatment is necessary.


All adults with any of the risk factors and all women age 60+ could benefit from a thyroid hormone test.


Adults with any of the risk factors for thyroid disease should have a thyroid function screening annually.

Schedule this Screening

*Screening availability may be limited by location.

More about Thyroid Function Screening

T4 is called that because it has four iodine atoms. It is converted to triiodothyronine (T3) when the extra iodine atom is removed.

The thyroid and the pituitary act like a heater and a thermostat which is why thyroid malfunction causes people to feel cold or hot.5