Section1

Underactive Thyroid Can Be Difficult to Diagnose

Colorado Thyroid Disease Prevalence Study

Colorado Statewide health fair in 1995 looked at 25,862 participants to assess thyroid function. Participants responded to a 14-question hypothyroid symptom questionnaire, which was based on results from a previous study.1

Pinch to zoom

  • Patients may not have signs and symptoms of hypothyroidism and, as a result, may not be properly diagnosed1
  • Symptoms of underactive thyroid can be mild, vague, or easily confused with those of other diseases (eg, depression)2
  • At times, symptoms may be assumed to be a part of the natural process of aging2
Section2

Symptoms of Hypothyroidism

Some people with hypothyroidism are asymptomatic, while others experience many of the following symptoms1-4:

  • Bradycardia
  • Brittle nails
  • Coarseness or loss of hair
  • Cold intolerance
  • Constipation
  • Decreased concentration
  • Depression
  • Dry or yellow skin
  • Fatigue
  • Goiter
  • Hoarseness
  • Infertility
  • Irregular or heavy menses
  • Mental impairment
  • Myalgias
  • Puffy face
  • Reflex delayed relaxation phase
  • Weight gain from fluid retention

A physical exam can be a helpful tool for diagnosing hypothyroidism. The patient care team will also check to see if there's a family history of thyroid conditions or other autoimmune diseases.4

Pinch to zoom

Section3

Blood Tests

A TSH test can initially test thyroid function and show if it is working properly.5

A free T4 (FT4) test can be ordered along with a TSH test to accurately determine how the thyroid gland is working.5

T4 (thyroxine) is found in 2 forms in the blood: T4, bound to proteins, and FT4, available to enter tissues.5

EUTHYROID

A normal TSH level means the pituitary gland and the thyroid gland are producing the right balance of TSH and thyroid hormone.5

HYPOTHYROIDISM

High TSH levels and low T4 levels mean the thyroid gland is not producing enough thyroid hormone (underactive thyroid or hypothyroidism), which causes the pituitary gland to secrete more TSH.5

Section4

Algorithm for Evaluating Suspected Hypothyroidism6

See how this algorithm may help you and the doctor verify if a patient has underactive thyroid.

Pinch to zoom

*TSH reference ranges may vary depending on the laboratory.

References:
  1. Canaris GJ, Manowitz NR, Mayor G, Ridgway EC. The Colorado thyroid disease prevalence study. Arch Intern Med. 2000;160(4):526-534.
  2. Braverman LE, Cooper DS, eds. Werner and Ingbar's The Thyroid: A Fundamental and Clinical Text. 10th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2012.
  3. Baskin HJ, Cobin RH, Duick DS, et al; for American Association of Clinical Endocrinologists. American Association of Clinical Endocrinologists medical guidelines for clinical practice for the evaluation and treatment of hyperthyroidism and hypothyroidism. Endocr Pract. 2002;8(6):457-469.
  4. Garber JR. Thyroid Disease: Understanding Hypothyroidism and Hyperthyroidism. 4th ed. Boston, MA: Harvard Health Publications; 2015.
  5. Thyroid function tests. American Thyroid Association website. http://www.thyroid.org/thyroid-function-tests/. Accessed March 21, 2016.
  6. Gaitonde DY, Rowley KD, Sweeney LB. Hypothyroidism: an update. Am Fam Physician. 2012;86(3):244-251.

Do you know how often your patients are screened for thyroid disorders?

NEXT HOW TO TREAT