Hypothyroidism is the name of the disease in which the thyroid gland produces insufficient amounts of its hormones. As the primary goal of thyroid hormones is to control body metabolism, it is understandable that people with hypothyroidism have symptoms associated with a slow metabolism.
Hypothyroidism is a very common condition throughout the world. It is estimated that up to 10% of women have some degree of thyroid dysfunction, many of them, however, still unaware of this fact.
Goiter is the name given to enlarged thyroid gland, which becomes easily noticeable as a bulging in the anterior region of the neck. Goitre may occur in hypothyroidism, hyperthyroidism, iodine deficiency, and thyroiditis. Goiter may also appear due to the appearance of multiple nodules in the thyroid, being called multinodular goiter in this case.
In hypothyroidism, as there is a lack of thyroid hormones, the brain increases the production of TSH, a hormone that stimulates the thyroid. With increased TSH in the blood, the thyroid gland begins to grow in an attempt to produce more thyroid hormones.
In most cases, goiter causes no symptoms and is only an aesthetic drawback. However, if the thyroid gland grows too tight it can compress the structures that pass through the neck, such as the esophagus and the trachea, leading to coughing, difficulty swallowing, hoarseness, and even difficulty breathing.
Because thyroid hormones are essential to our metabolism, that is, to the way the body generates and expends energy, the lack of thyroid hormones causes signs and symptoms of slowed metabolism. Among them, the most common are:
Cold intolerance
Speech and movements slowed down
Dismay
Difficulty concentrating
Weight gain*
* Warning, weight gain in hypothyroidism is usually a few pounds and is also closely related to fluid retention. No one becomes obese just by having hypothyroidism.
Hypothyroidism causes a decrease in blood supply to the skin, making it paler and colder. The pallor of the skin can also be caused by anemia, a common finding in this disease.
Hair loss is a frequent finding and the nails become brittle. The patient also has a lower ability to sweat.
Patients with hypothyroidism have an accumulation of two substances, called hyaluronic acid and chondroitin sulfate. Both are deposited on the skin and form a kind of gelatin when mixed with water. Therefore it is common to have a thickening of the most superficial layer of the skin, making it thicker and more dry.
In cases of severe hypothyroidism there may be fluid retention in the legs and rest of the body, which mix with these two substances forming a hard edema, called myxedema.
The lack of thyroid hormones causes a decrease in contractility of the heart muscle and its ability to pump blood. The result is less tolerance to physical exertion and easy fatigue.
Patients with hypothyroidism often have elevated cholesterol.
High blood pressure is also a common finding. In patients who were previously hypertensive, blood pressure tends to be higher and there is a need to increase the medication.
Muscle pain and cramps are the most common muscle changes in hypothyroidism. In some cases there is spontaneous muscle injury (called rhabdomyolysis) with intense muscle pain and weakness, especially in the hip, thigh and shoulder muscles.
In relation to the joints, joint pain is the most common symptom.
Patients with hypothyroidism have higher uric acid levels than the average population, and are therefore at a higher risk of developing gout.
Another common alteration is carpal tunnel syndrome, which usually regresses without the need for surgery after the onset of thyroid hormone replacement.
Women with hypothyroidism may have changes in menstruation, ranging from a reduction or even absence of the period, to increased bleeding and menstruation time. These menstrual changes may not improve even after starting treatment.
Untreated hypothyroidism also increases the chance of infertility. In those who can get pregnant, there is a higher risk of miscarriage.
In men, hypothyroidism causes erectile dysfunction and difficulty ejaculating. Both men and women have decreased libido.
The most common gastrointestinal symptom of hypothyroidism is constipation. Another common symptom is altered taste, which causes a decrease in the taste of food.
Atrophy of the stomach mucosa (gastric atrophy) may occur. The occurrence of celiac disease is four times higher in patients with hypothyroidism than in the general population.
There may also be an increase in the size of the tongue, which usually leads to obstructive sleep apnea.