Hypothyroidism

Partial or total loss of thyroid gland function due to inadequate synthesis or resistance to the action of thyroid hormones. Since these molecules play a vital role in almost all tissues, their decrease or absence will manifest in many of the body's systems. It is one of the most common diseases worldwide, affecting up to 5% of the population.

There may be various causes related to hypothyroidism:

• Autoimmune disorders: the most common cause of hypothyroidism is Hashimoto's thyroiditis, due to the production of antibodies against the thyroid gland. However, the exact triggers of this disease are unknown, although a combination of genetic and environmental factors has been suggested.
• Response to treatment for hyperthyroidism with radioactive iodine or antithyroid medications used to normalize thyroid function, which triggers permanent hypothyroidism.
• Thyroid surgery involving the removal of all or part of the thyroid gland.
• Radiation therapy treatment for head and neck cancer.
• Medications used in the treatment of other diseases (amiodarone, lithium, interferon-alpha, interleukin-2).
• Thyroiditis or inflammation of the thyroid gland due to infections, congenital thyroid disease with a defective or absent thyroid gland, or pituitary gland disorders involving the absence of stimulation of the thyroid gland, infiltrative thyroid disorders.
• Pregnancy can trigger the production of antibodies against the thyroid gland. If left untreated, it can increase the risk of miscarriage, premature birth, and preeclampsia or fetal development issues.
• Iodine deficiency, as it is essential for the production of thyroid hormones. Iodine deficiency can cause hypothyroidism, while excess iodine can worsen pre-existing hypothyroidism.

Additionally, a series of factors have been described that can increase the risk of hypothyroidism:

• Age: the risk increases with age, especially after the age of 60.
• Gender: women are at higher risk of hypothyroidism than men.
• Having other autoimmune diseases such as type 1 diabetes, celiac disease, rheumatoid arthritis.

The signs and symptoms of hypothyroidism vary depending on the severity of the hormone deficiency and may differ from person to person. In the early stages, the symptoms of hypothyroidism are barely noticeable, and as the disease slowly progresses, they become more evident. Some common symptoms include:

• Fatigue and tiredness.
• Weight gain.
• Cold intolerance.
• Joint and muscle pain, cramps.
• Dry and scaly skin, brittle and weakened hair and nails.
• Loss of libido.
• Irregular or heavy menstrual periods, fertility problems.
• Slow heart rate.
• Depression.
• Slow movements and thinking.
• Constipation.
• High cholesterol levels.
• Swelling of the face, hands, and feet.

Additionally, children may experience slower growth and development, teenagers may start puberty earlier than normal, and older adults may develop memory problems along with depression.

Hypothyroidism cannot be prevented, but it is easily manageable if detected early and the appropriate treatment is initiated. The best way to prevent a severe form of the disease or for the symptoms to limit quality of life is to be aware of possible symptoms and consult your doctor if you experience any.