What is Hypothyroidism?

What is Hypothyroidism?

Table of Contents

• Hypothyroidism (Lazy Thyroid Gland) 
• Clinical Manifestations of Hypothyroidism
• Treatment of Hypothyroidism

Hypothyroidism (Lazy Thyroid Gland) 

The main clinical signs of hypothyroidism are weight gain with fatigue and weakness, hair loss and poor memory.

The clinical picture that develops as a result of inadequate secretion of thyroid hormones is called hypothyroidism. Thyroid hormone deficiency can be of varying degrees and can manifest itself in different clinical forms ranging from subclinical hypothyroidism, which is difficult to recognize, to severe hypothyroidism. The main cause of thyroid hormone deficiency is the autoimmune disease “Hashimoto's thyroiditis”. As the autoimmune process gradually decreases thyroid function, there is a compensation period during which normal thyroid function is maintained by an increase in TSH.

The annual incidence of autoimmune hypothyroidism is about 4 per 1000 women and 1 per 1000 men. Subclinical hypothyroidism is found in 6-8% of women and 3% of men. The incidence of hypothyroidism increases with age in both sexes. Hashimoto thyroiditis is considered if TSH is elevated, free T4 is normal or low and anti-TPO/anti-TG is elevated. As with most autoimmune disorders, predisposition is determined by a combination of genetic and environmental factors. There is an increased risk of autoimmune thyroid diseases among siblings, parents and relatives.

Clinical Manifestations of Hypothyroidism

The main clinical signs of hypothyroidism are weight gain with fatigue and weakness, hair loss and poor memory. Some patients may have dry skin, chills and constipation. Swelling and edema of the hands, feet and face are common findings. The onset of the disease is usually insidious. In some patients, the thyroid gland may enlarge. The gland is usually irregular and hard in consistency. There is often a yellowish pallor due to carotene accumulation. Hair is dry, brittle and falls out easily.

Weight gain despite lack of appetite is due to fluid accumulation in the tissues. In untreated cases, heart rate slows down and pericardial effusion may be observed. Due to fluid accumulation in serous cavities in the middle ear, conductive deafness may be observed. On physical examination, tendon reflexes are slowed down. Painful carpal tunnel syndrome may be detected in the wrists. In advanced hypothyroidism, hoarse voice, enlargement of the tongue and speech difficulties are observed.

Autoimmune hypothyroidism may be associated with other autoimmune diseases such as vitiligo, pernicious anemia, Addison's disease, alopecia areata and type 1 diabetes. Iron deficiency anemia and elevated cholesterol can often be detected in hypothyroidism. In Hashimoto's thyroiditis, thyroid ultrasonography findings, increased vascularity, decreased echogenicity, pseudonodular appearances with heterogeneous structure are typical.

Hypothyroidism also occurs after iodine deficiency, surgical treatment of the thyroid gland and ablation of the thyroid gland with radioactive iodine. Complete surgical removal of the thyroid gland results in absolute hypothyroidism, whereas mild hypothyroidism after subtotal thyroidectomy resolves within a few months as a result of stimulation of the gland remnants with increased TSH. Amiodarone group heart rhythm regulator drugs and some antipsychotic drugs such as lithium may also cause hypothyroidism.

Treatment of Hypothyroidism

Hypothyroidism treatment is an easy treatment after the diagnosis is confirmed. The thyroid hormone “levothyroxine” is given to the patient as a replacement as much as the body needs, one dose a day, in the morning on an empty stomach, half an hour before breakfast. Once thyroid hormone replacement is complete and TSH levels are stable, follow-up treatment once or twice a year is usually sufficient.