Thyroid Dysfunction Management

Diagnosis and Treatment Considerations

The presence of symptoms compatible with hypothyroidism is a consideration for treatment, according to the American Society of Clinical Oncology 1
In patients with cancer treated with immunotherapy, treatment should be considered even with subclinical hypothyroidism if fatigue or other symptoms are present, as recommended by the American Society of Clinical Oncology 1
The American College of Physicians recommends TSH and free T4 testing for case detection in symptomatic patients and as part of routine monitoring in specific high-risk populations, but universal screening in asymptomatic adults is not recommended, with moderate strength of evidence 2
Patients with type 1 diabetes should be tested for TPO antibodies soon after diagnosis, and thyroid-stimulating hormone (TSH) concentrations should be measured at diagnosis when clinically stable or after glycemic control has been established, as recommended by the American Academy of Family Physicians and the American College of Physicians 3, 4
Pregnant women should have TSH monitored every 4 weeks until stable, then once per trimester, and maintain TSH within trimester-specific reference ranges, including a TSH level of less than 2.5 mIU/L in the first trimester and less than 3.0 mIU/L in the second and third trimesters, as recommended by the American Academy of Family Physicians, the American Thyroid Association, and the American College of Obstetricians and Gynecologists 5, 6, 7, 1, 8, 9

Monitor TSH every 1-2 years in euthyroid individuals with positive TPO antibodies due to increased risk of developing hypothyroidism, and every 1-2 years or sooner if symptoms develop in patients with type 1 diabetes 3
The following table outlines the monitoring frequency based on TSH levels:

TSH Level	Monitoring Frequency
0.1-0.45 mIU/L	every 3 months
<0.1 mIU/L	every 4-6 weeks

The European Society of Medical Oncology recommends initiating propranolol or atenolol for symptomatic relief of hyperthyroidism symptoms, such as tachycardia, tremors, and anxiety, in patients with hyperthyroidism 1
Treatment is recommended for patients with TSH <0.1 mIU/L who are older than 60 years, have or are at risk for heart disease, have osteopenia/osteoporosis, are estrogen-deficient women, or have symptoms suggestive of hyperthyroidism, according to the American Medical Association 10
Subclinical hyperthyroidism is defined as decreased serum TSH with normal free T4 and T3 levels, and is classified by severity: Mild (TSH 0.1-0.45 mIU/L) and Severe (TSH <0.1 mIU/L), as recommended by the American Medical Association 10

Implement good sleep hygiene practices, including regular sleep schedule, avoiding caffeine and alcohol before bed, and creating a dark, quiet sleep environment, to improve sleep quality and reduce fatigue, as recommended by the National Sleep Foundation 11
Assess activity level and consider a gradual exercise program, starting with low-level activities and gradually increasing, to improve overall health and reduce fatigue, as recommended by the American College of Sports Medicine 12

A comprehensive laboratory panel for patients presenting with low energy should include complete blood count, urinalysis, serum electrolytes, blood urea nitrogen, serum creatinine, fasting blood glucose, lipid profile, liver function tests, and thyroid-stimulating hormone, according to the American Heart Association 13
Serum ferritin, serum iron, total iron binding capacity, and transferrin saturation should be measured to determine if iron deficiency is the cause of anemia, as recommended by the European Society of Cardiology 14
Vitamin B12 and folate levels, vitamin D levels, and inflammatory markers should be measured, as deficiencies can cause anemia and neurological symptoms, and autoimmune conditions may be suspected, according to the British Association of Dermatologists 15