Hypothyroidism in middle-aged people

Thyroid function changes with age. Typically TSH increases, while T4 levels stay mostly unchanged, and T3 levels drop (1, 2).

Most hypothyroidism diagnoses occur during middle age.

Signs of hypothyroidism in middle-aged people

Symptoms of an underactive thyroid can often be confused with symptoms of heart problems, neurological disorders, or gastrointestinal disorders (3). The most common symptoms are (4):

  • Fatigue
  • Slow digestion
  • Brain fog
  • Weight gain
  • Problems with sleeping

Hypothyroidism in middle-aged people can exacerbate already present diseases, such as (5):

  • Anemia (with unusually large red blood cells and low hemoglobin, macrocytic anemia)
  • High cholesterol (hypercholesterolemia)
  • Kidney dysfunction

How the thyroid changes as people age

The thyroid shrinks and becomes flatter with age — it can’t use up as much iodine and the process of converting T4 to T3 slows down (6).

Having lived in an iodine-deficient region will also cause TSH levels to decrease with age (7, 8).

The risk of developing an underactive thyroid is about four times higher for middle-aged women compared to people in their early and mid-twenties (9, 10).

Treating an underactive thyroid in middle-aged people

Treatment with L-thyroxine is recommended for hypothyroidism. Starting with lower doses — around 25 micrograms — and if necessary, gradually increasing every 2–4 weeks (4).

People usually need higher doses of L-thyroxine if on hormone therapy related to menopause (4).

It’s debated whether or not a treatment should be started if the thyroid is only slightly underactive in middle-aged people. Healthcare providers might test for additional factors, such as: high blood pressure, history of smoking, goiter, positive TPO antibodies, diabetes, and high cholesterol levels (11).

Taking care of your thyroid health in middle age

Talking with your healthcare provider can help with earlier diagnosis, setting up an appropriate treatment regimen, and adjusting your lifestyle in order to improve your overall wellbeing.

How we write: our information is based on the results of peer reviewed studies using the National Library of Medicine platform. It is written by scientists and reviewed by external experts. If you believe we might have overseen crucial scientific information, please contact us at hello@boostthyroid.com

Disclaimer: This information is not intended to mitigate, prevent, treat, cure or diagnose any disease or condition. If you want to change your treatment, lifestyle, your diet, include supplements in your diet or have concerns about your health, please consult your doctor before trying new approaches.


  1. Brener AP, et al. Age-related changes in thyroid function: a longitudinal study of a community-based cohort, 2012
  2. Surks MI, et al. Age-specific distribution of serum thyrotropin and antithyroid antibodies in the US population: implications for the prevalence of subclinical hypothyroidism, 2007
  3. Mitrou P, et al. Thyroid disease in older people, 2011
  4. Gietka-Czernel M. The thyroid gland in postmenopausal women: physiology and diseases, 2017
  5. Duntas, LH. Thyroid Function in Aging: A Discerning Approach, 2018
  6. Mariotti S, et al. The ageing thyroid, 1995
  7. Hoogendoorn EH, et al. Thyroid function and prevalence of anti-thyroperoxidase antibodies in a population with borderline sufficient iodine intake: influences of age and sex, 2006
  8. Völzke H, et al. Reference intervals of serum thyroid function tests in a previously iodine-deficient area, 2005
  9. Tunbridge WMG, et al. The spectrum of thyroid disease in a community: the Whickham survey, 1977
  10. Vanderpump MPJ, et al. The incidence of thyroid disorders in the community: a twenty-year follow-up of the Whickham Survey, 1995
  11. Biondi B, et al. The clinical significance of subclinical thyroid dysfunction, 2008

Photo: Unsplash; Design: VLM Health



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