Treating mild hypothyroidism: Benefits still uncertain – Harvard Health Blog
Your thyroid, a tiny butterfly-shaped gland located in front of your windpipe (windpipe) and below your voice box (larynx) can have a profound impact on your health and well-being. Throughout life, your thyroid is constantly producing hormones that influence your metabolism. These hormones affect your mood, energy, body temperature, weight, heart, etc.
A brief overview of hypothyroidism
Your thyroid produces two types of thyroid hormones: T4 or thyroxine and T3 or triiodothyronine. These hormones influence every cell, tissue, and organ in your body, from your muscles, bones, and skin to your digestive tract, brain, and heart, by controlling the speed and efficiency with which cells convert nutrients into energy – a chemical activity. known as metabolism.
The thyroid gland is under the influence of the pituitary gland. No larger than a pea and located at the base of the brain, the pituitary gland controls the production of thyroid hormones by the thyroid by releasing thyroid stimulating hormone (TSH).
The levels of TSH in your bloodstream rise or fall depending on whether there is enough thyroid hormone to meet your body’s needs. Higher levels of TSH cause the thyroid to make more thyroid hormones, while lower levels signal the thyroid to make less.
Hypothyroidism occurs when the thyroid fails to produce enough thyroid hormones to meet the body’s needs, thereby slowing down the metabolism. In a person with overt hypothyroidism, thyroid hormone levels are lower than normal and TSH levels are much higher than normal.
What is mild hypothyroidism?
Subclinical or mild hypothyroidism does not meet the standard definition of hypothyroidism. In mild hypothyroidism, you may or may not have symptoms and your T4 and T3 levels are normal, but your TSH levels are slightly elevated. Mild hypothyroidism is diagnosed by a blood test.
More than 10 million adults in the United States have hypothyroidism, the vast majority of which are subclinical.
What are the risks of not treating mild hypothyroidism?
Whether or not to treat mild hypothyroidism has been a topic of study and debate for years. What worries doctors the most with mild hypothyroidism is the potential link between untreated mild hypothyroidism and coronary artery disease. The research findings on whether subclinical thyroid disease causes heart problems are conflicting. The disease has been linked to heart and vascular abnormalities, and studies indicate that treating mild hypothyroidism can improve various markers of the structure and function of the heart.
However, a recent study published in the Journal of the American Medical Association can make doctors think. The researchers studied people with mild hypothyroidism who had also had a heart attack. They treated one group of these patients for their mild hypothyroidism and left the condition untreated in the other group. The study showed that people treated for mild hypothyroidism did not have better heart function than those who were not treated.
What are the disadvantages of treating mild hypothyroidism?
When mild hypothyroidism is treated, levothyroxine (T4) is the treatment of choice.
A 2017 essay published in The New England Journal of Medicine found that treating people aged 65 and over for mild hypothyroidism does not have much benefit. The authors found no real difference in symptoms between participants who received levothyroxine and those who received placebo. The authors claim that many older people return to normal thyroid function on their own, without treatment. A recently published follow-up study in the Annals of Internal Medicine analyzed the data of patients registered in 2017 NEJM study, and found that even those with the most symptoms did not benefit.
Besides the possibility that the treatment will not provide any benefit, there are other reasons for caution. Overtreatment – prescribing thyroid medication to someone with subclinical disease who may not need treatment, or overtreatment for the thyroid – carries serious risks, especially thyrotoxicosis, presence of too much thyroid hormone in the body. It happens frequently; estimates suggest that 20% or more of people treated with thyroid hormone suffer from thyrotoxicosis. Long-term complications of even mild thyrotoxicosis can include heart problems and bone loss.
Consider the risks and benefits of treatment
If you are weighing the pros and cons of treating hypothyroidism, discuss the following questions with your doctor:
- How can I benefit from treatment? Could it treat my symptoms? Prevent heart disease? Help me design?
- What are the risks of treatment?
- How will we know if the treatment is working and how long will it take to find out?
- How long will I have to continue the treatment?
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