Diagnosis of Hypothyroid Disease

Diagnosis of Hypothyroid Disease

Case study: You are cross-covering for two of your business partners who have left town for much-needed vacations during the holiday season. Your next patient, a 42-year-old woman named Virginia, is regularly seen by another physician in your practice. But you are seeing her today because the clinic called her this morning to follow up on some abnormal labs. When you quickly flip through her medical chart, you see that the abnormal lab values flagged in the chart were an elevated TSH and a low level of the hormone thyroxine. You knock on the door and enter the exam room.

Virginia is a well put-together woman in no apparent distress. Her vital signs this morning include a temperature of 98.6 F, heart rate of 55, and respiratory rate of 16. She has a BMI of 28. You greet her and introduce yourself. What do you want to ask her first?

You ask her why she initially came to see your partner in clinic. Virginia tells you that she has been feeling very fatigued lately. She has barely been able to get through her days without taking a nap, and she has definitely not been making it to the gym. She doesn’t have the energy to cook healthy meals, either. As a result, she thinks her fatigue may be the reason she has been gaining weight and has been suffering from worsening constipation. What do you do next?

You ask Virginia about her prior medical history, perform a physical exam, and discuss the latest lab findings with the patient. Virginia tells you that she has a history of depression and hypercholesterolemia for which she is taking an SSRI and a statin. On physical exam, Virginia’s heart rate is slightly slow but regular, lungs are clear to auscultation, and her abdomen is soft and non-tender. Her face is a little puffy, but she does not have any goiter, palpable nodules on her thyroid, pallor or distal extremity swelling. She has some knee joint tenderness bilaterally, but no other joint tenderness. These findings are consistent with the clinical manifestations of hypothyroidism, which include bradycardia, cold sensitivity, constipation, depression, dry skin, face puffiness, fatigue, goiter, hair loss, hoarseness, hypercholesterolemia, infertility, memory loss, menstrual abnormalities, muscle and joint pain, and thinning hair. Many of these symptoms come on over the course of months to years, and the physical findings may be subtle. You commend your colleague for thinking to order a thyroid panel. What do you tell your patient about her labs and recommended management of her hypothyroidism?

You tell Virginia that she was called back to clinic because her lab work was consistent with hypothyroidism, a condition where the thyroid does not produce enough thyroid hormone for the body to function effectively. A low thyroid level is the most likely cause of her fatigue and possibly other symptoms, as well. You ask her if she has had a history of neck surgery, neck radiation, radioactive iodine or other anti-thyroid hormone medication, or if she recently had a baby. You also ask her if she has a family history of thyroid disease. She tells you she has not had any of those risk factors. You then let her know that the most likely cause of her hypothyroidism is autoimmune disease. Although you will have to follow her thyroid levels chronically, the good news is that clinically symptomatic hypothyroidism responds well to levothyroxine. As long as she follows up in a few weeks to make sure she is responding appropriately to her new medication and takes it as prescribed, her symptoms should improve and resolve.

For more information:

Mayo Clinic Staff. Hypothyroidism (Underactive Thyroid). Mayo Clinic Website. https://www.mayoclinic.org/diseases-conditions/hypothyroidism/symptoms-causes/syc-20350284. Accessed December 29, 2019.

Dr. V. Silverstein
Durham, NC

Published on 3/11/2020