What is Hypothyroidism ?
Hypothyroidism is a clinical syndrome caused by a deficiency of thyroid hormones. This condition usually results from insufficient production of these hormones by the thyroid gland or, in rare cases, from decreased biological activity of the hormones at the tissue level.
Prevalence
Hypothyroidism occurs significantly more often in women than in men (approximately 10:1 ratio). It is most commonly diagnosed in individuals aged 50–60, although it may be observed at any age.
Causes
The most frequent cause is autoimmune thyroiditis (Hashimoto’s thyroiditis), where the immune system produces organ-specific antibodies that damage hormone-producing thyroid cells, leading to decreased function of the gland.
Other possible causes include:
- Total or subtotal thyroidectomy (surgical removal of the thyroid gland)
- Treatment with radioactive iodine
- Use of antithyroid medications (sometimes prescribed inappropriately)
- Thyroid cancer or metastases to the gland
- Infiltrative diseases such as sarcoidosis, tuberculosis, or amyloidosis
- Severe iodine deficiency
When to Suspect Hypothyroidism
There are several nonspecific symptoms commonly seen in hypothyroidism, including:
- Generalized weakness
- Excessive sleepiness
- Slowed movements and speech
- Chronic fatigue
- Hair thinning or loss
- Dry skin
- Mild weight gain
- Poor memory
- Difficulty concentrating
- Frequent episodes of low mood or depression
- Sensation of irregular heart rhythm
- Bradycardia (slow heart rate)
- Decreased appetite
- Constipation
- Menstrual irregularities
- Infertility
- Sleep disturbances
Why Is It Important to Maintain Normal Thyroid Hormone Levels?
Thyroid hormone receptors are present in almost all organs and systems. These hormones are essential for regulating metabolism and maintaining proper function across all body systems. When thyroid hormones are deficient, metabolic processes slow down, leading to widespread functional impairments. Because the symptoms are nonspecific and overlap with many other conditions, diagnosis may be delayed. Patients often receive ineffective treatment from other specialists before being referred to an endocrinologist.
Hypothyroidism Diagnosis and Treatment
Diagnosis is made based on laboratory tests assessing thyroid function:
- Elevated thyroid-stimulating hormone (TSH)
- Normal or decreased levels of free thyroxine (FT4) and triiodothyronine (FT3)
Treatment
Hypothyroidism treatment is based on hormone replacement therapy with levothyroxine sodium. Therapy should be prescribed and monitored by an endocrinologist under proper medical supervision.