Thyroid disorders: Myths and medicine
-The thyroid is a small butterfly-shaped gland situated at the base of the neck. Unsplash
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“Doctor, I’ve put on 12 kilos because of my thyroid.” Or this one: “My thyroid tests are normal now. Why should I continue taking medicine?” Or perhaps the commonest of all: “Do I really have to take this tablet for the rest of my life?”
Few endocrine disorders are as common, or as misunderstood, as hypothyroidism, which results from an underactive thyroid gland. In India, it affects an estimated 10-15% of adults, particularly women and older individuals. Yet much of what patients believe about the condition comes not from medical science but from social media, the internet, or friends.
The thyroid is a small butterfly-shaped gland situated at the base of the neck. Despite its modest size, it exerts an extraordinary influence on the body by producing the hormones thyroxine (T4) and triiodothyronine (T3), under the effect of the thyroid-stimulating hormone (TSH), which is produced by the pituitary gland. These hormones regulate a host of metabolic processes throughout our bodies. When thyroid hormone levels fall, virtually every organ system slows down.
The symptoms of hypothyroidism often develop gradually. Fatigue, excessive sleepiness, dry skin, hair loss, puffiness of the face, constipation, sensitivity to cold, menstrual irregularities, impaired concentration, and slowing of the pulse are all recognised features. Unfortunately, none of these symptoms is specific to hypothyroidism. They are often attributed to other conditions, such as ageing, stress, or nutritional deficiencies. Equally, once hypothyroidism is diagnosed, it is blamed for almost every subsequent symptom, whether related or not.
No misconception is more widespread than the belief that hypothyroidism is a major cause of obesity. Patients are often relieved when they receive the diagnosis because they perceive that they have finally found an explanation for their weight gain. If you have mild or subclinical hypothyroidism (TSH <10, normal T3 and T4), you are unlikely to gain significant weight because of thyroid.
Even untreated severe hypothyroidism usually accounts for no more than two to four kilogrammes of weight gain, much of it due to fluid retention rather than excess body fat. Correcting hypothyroidism is not, by itself, a weight-loss treatment.
Another area rife with misinformation is diet. There is no scientifically proven “thyroid diet.” Patients are frequently advised to eliminate gluten, dairy products, cabbage, broccoli, cauliflower or soy. Scientific evidence does not support these restrictions. When eaten as part of a normal diet in an iodine-sufficient population such as India, they have negligible clinical significance.
Not everyone with mild hypothyroidism requires treatment. Of those who do, many hesitate to start treatment because they are told it will be lifelong. The medication itself is not addictive. It is lifelong because the disease usually is. In most adults, hypothyroidism results from Hashimoto’s thyroiditis, an autoimmune disorder in which the immune system gradually damages the thyroid gland. Thyroxine simply replaces what the body can no longer make. Hypothyroidism may also occur after thyroid surgery, radiation,or because of medications. Rarely can a malfunctioning of the pituitary gland cause “secondary” hypothyroidism.
Patients often ask: “If my reports are normal now, why should I continue the medicine?” The answer is that your thyroid hormone levels are normal because the medication is replacing the hormone your thyroid cannot produce. Stopping treatment will cause thyroid hormone abnormalities again. The medicine has controlled the condition; it has not cured it.
Fortunately, thyroxine remains one of the safest and most effective medications in modern medicine. It restores normal thyroid hormone levels and reverses almost all the manifestations of hypothyroidism. However, excessive doses may increase the risk of irregular heart rhythm and accelerate bone loss. Regular monitoring helps ensure that the dose remains appropriate.
Another source of anxiety is the thyroid antibody report. Many patients are alarmed to discover that their thyroid peroxidase antibody levels are very high despite taking treatment. These antibodies simply confirm autoimmunity (Hashimoto’s disease). They do not require treatment in their own right. It is the TSH and thyroid hormone levels that guide management.
Who should be tested? Testing is strongly advised for newborn babies because some may be born with a defective or absent thyroid gland, and early treatment prevents permanent intellectual disability. Women planning pregnancy, or those who become pregnant, should have thyroid function assessed since even mild hypothyroidism may affect pregnancy outcomes and foetal brain development. Testing is also appropriate for individuals with autoimmune diseases, a strong family history of thyroid disorders, children with poor growth, women with infertility or menstrual disturbances, and people taking medications such as amiodarone or lithium. Remember, though, to stop biotin-containing supplements before getting tested, as they can interfere with the lab measurement.
Hypothyroidism is one of the commonest endocrine disorders –and one of the easiest to treat. With an accurate diagnosis, the correct dose of thyroxine and periodic monitoring, most people can expect normal health, normal longevity and an excellent quality of life.
The author is head of Endocrinology and Diabetes at Max Healthcare. The views expressed are personal.
-Khmer Times-
