Hypothyroidism: hypothyroidism is the clinical situation produced by a deficit in the activity of thyroid hormones, it is more frequent in women and its frequency is high, especially in people over 60 years of age. What are the causes of hypothyroidism? In 95% of cases we speak of a primary hypothyroidism and what we mean by primary hypothyroidism, it means that the defect will be found in the thyroid gland. Now the most common cause in the world is iodine deficiency, especially in endemic areas, why? because the most common cause in developed countries is chronic autoimmune thyroiditis or also known as Hashimoto's thyroiditis. Other main causes of primary hypothyroidism are thyroid dysgenesis, mainly when we see congenital hypothyroidism, we also talk about thyroid ablation either by radioactive iodine or thyroid surgery, another main cause is also the drugs that will either contain iodine or that can interfere with its organization as amiodarone, lithium, antithyroid drugs and tyrosine kinase inhibitors are very well known. Now that happens in 95% of cases, in a primary hypothyroidism, but what happens with a secondary hypothyroidism , it is called secondary when the involvement is in the pituitary gland, it will be called tertiary when the involvement is in the hypothalamus, and another etiology we will have to the peripheral resistance of the thyroid hormones, that this affectation is very rare. Now let's move on to see the signs and symptoms of hypothyroidism: the signs and symptoms of hypothyroidism are nonspecific, that is why the diagnosis is based mainly on laboratory tests, for example we can see hypothyroidism in childhood, we have here at Congenital hypothyroidism, congenital hypothyroidism is difficult to recognize clinically and for this to avoid diagnostic delay, systematic screening tests are performed on all newborns at 48 to 72 hours of life, generally we can see a birth weight more than 4 kilograms , there will be feeding problems, a hoarse cry, prolonged jaundice , umbilical hernia, constipation or defective closure of the fontanelles. Now, if congenital hypothyroidism is not diagnosed and is not treated in time, it produces serious alterations in physical and mental development that lead to a clinical picture called cretinism. In cretinism we will see mental retardation, a short stature with delayed bone age, a prominent abdomen , dry skin, a typical fascies with periorbital edema and macroglossia. And in childhood, if hypothyroidism is not congenital, there will be a further accentuation of short stature, delayed sexual maturation and puberty, as well as learning difficulties, apathy and lethargy. Now the adult signs and symptoms. The clinical picture in adults will be insidious and progressive, and the entire clinical picture with adults will be summarized in hypometabolism plus myxedema. Hypometabolism we refer to the slowing down of the metabolism and when we speak of myxedema we speak of a type of mucosal edema that does not generate godete. And what are the signs and symptoms that we can find? We can find alopecia, bradypsychia, memory loss, macroglossia, eyelid edema, we can see a goiter or a non- palpable thyroid , an intolerance to cold, cardiomegaly, pericardial effusion, metrorrhagia, an associated carpal tunnel syndrome, constipation, weakness, spasticity, rough, dry, yellow skin, weight gain and an associated slowed Achilles reflex and if you notice these signs and symptoms are nonspecific, that is why the diagnosis is made primarily with laboratory tests. If the patient has severe hypothyroidism and does not receive treatment, he or she may develop a severe condition with stupor and hypothermia that can be fatal. We are talking about a myxedematous coma: myxedema coma is a severe hypothyroidism with a multisystemic compromise and with a progressive deterioration of consciousness that appears especially in the elderly, in the presence of a predisposing factor , a predisposing factor such as exposure to cold , infections or sedative drugs, here in myxedematous coma there must be a high clinical suspicion for its diagnosis, because myxedema coma can present a high mortality. The diagnosis is made mainly with thyrotropin or also called as thyroid stimulating hormone and with thyroxine. In 95% of the cases, as I told you, a primary hypothyroidism, T4 will be decreased and as a compensatory effect, TSH will be increased, when the defect is in the pituitary or hypothalamus it is called central hypothyroidism: T4 will be decreased, but here comes the difference, the TSH will be normal or decreased, unlike the primary one, which will be increased here, we must take that difference into account. And when we talk about a subclinical hypothyroidism, T4 will be normal and TSH will be increased, obviously if in hypothyroidism there is a deficit of thyroid hormones, the treatment will be based on substitution and is carried out with levothyroxine and eye when we talk about subclinical refers to the absence of the clinical signs of hypothyroidism, we are simply referring to a biochemical state: where T4 will be normal and TSH will be increased and not all people receive treatment for subclinical hypothyroidism, those with a TSH greater than 10 receive treatment , in pregnant women, or who have pregnancy wishes, in children and adolescents. And what about those with a TSH between 5 and 10: those with symptoms receive treatment , the symptoms obviously compatible with hypothyroidism, if there is a goiter or if there is a thyroid autoimmunity, but who should not be treated in subclinical hypothyroidism : we should not treat the elderly or heart patients with a TSH below 10. And the treatment of a myxedema coma will be supportive treatment, then the treatment will be given with intravenous hydrocortisone , eye hydrocortisone before levothyroxine to avoid an adrenal crisis And this is how we culminate in the summary of hypothyroidism. LIKE IT, SHARE AND SUBSCRIBE.
