Hypothyroidism is a state of underactive thyroid gland, meaning the gland simply can’t make enough thyroid hormone to maintain normal body functions and metabolism. The most common cause of hypothyroidism in iodine sufficient areas is Autoimmune Thyroiditis (Hashimoto) followed by; thyroidectomy (surgical removal of thyroid), radioactive iodine ablation of the thyroid (usually for treatment of hyperthyroidism), postpartum thyroiditis (inflammation of the thyroid after delivery), and other rare causes including drugs, congenital (from birth), infiltrating diseases and pituitary/hypothalamic disorders. Iodine deficiency is a cause of hypothyroidism and goiter in places where there is not enough iodine in diet, however this has become rare especially in most countries where there is adequate intake of iodized salt and foods rich in iodine.
Hashimoto’s Thyroiditis – more common in females than males, is a condition in which the immune system attacks the thyroid and results in inflammation known as chronic lymphocytic thyroiditis. This type of inflammation can develop suddenly or gradually and most of the time it leads to underactive thyroid gland (hypothyroidism). One of the tests used to diagnose Hashimoto is a blood test done to detect Thyroid Peroxidase (TPO) antibody, which is present in more than 90% of people with Hashimoto. However this test can be positive in up to 10% of the general population without hypothyroidism, making this test a confirmatory test rather than a screening test for Hashimoto.
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Signs and symptoms of Hypothyroidism:
As explained above, when there is deficiency of thyroid hormones the body’s metabolism and functions decrease/slow down. Regardless of the cause of hypothyroidism, the signs and symptoms are generally the same and include:
Tiredness/fatigue/sluggishness
Weight gain
Abnormal/irregular menstrual cycles
Constipation
Cold intolerance
Dry skin
Brittle nails
Hair loss
Slow heart rate
Growth failure in children
Generalized swelling of legs
Depression and cognitive dysfunction
Puffy face (especially in severe and prolonged hypothyroidism)
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Diagnosing Hypothyroidism
Since most of the above symptoms can be common even in the absence of hypothyroidism, the best way to find out if you have an underactive thyroid is to measure thyroid hormones via a blood test. This is a simple test that utilizes the negative feedback mechanism explained above, your doctor will send for a blood test for TSH and free-T4 levels which should be sufficient enough to assess the function of the thyroid (TSH will be high and free T4 low in hypothyroidism)
Treatment
Regardless of the cause of hypothyroidism, treatment is generally the same with the exception of some transient and/or subclinical hypothyroidism where observation can be a better option. Treatment involves replacing thyroid hormone with a synthetic form of thyroid hormone taken as a pill, some people prefer to take a natural form of thyroid (Armour, Nature Thyroid etc.) however most thyroid guidelines recommend replacement with just the synthetic hormone.
Since most of the above symptoms can be common even in the absence of hypothyroidism, the best way to find out if you have an underactive thyroid is to measure thyroid hormones via a blood test. This is a simple test that utilizes the negative feedback mechanism explained above, your doctor will send for a blood test for TSH and free-T4 levels which should be sufficient enough to assess the function of the thyroid (TSH will be high and free T4 low in hypothyroidism)