hypothyroidism a autoimune endocrine disorder

it is 2endocrine disorder that is caused autoimune

1. HYPOTHYROIDISM Aaqib nawaz wassan Abdul moiz soomro

2. Hypothyroidism is defined as a deficiency in thyroid harmone secretion. This disorder occurs in 2 to 15% of the population, more commonly in women than in men. The risk of developing hypothyroidism increases with age. When there is low thyroid harmone a variety of clinical signs and symptoms of hypometabolism develops. Defination:

3. Cardiovascular system Respiratory system Renal system Central nervous system Neuromuscular system Gastrointestinal system Hematology Effect of hypothyroidism on different organ system:

4. Hypothyroidism is characterized by a decrease in oxygen and substrate utilization by all the major organ systems of the body. As a result, the demands for cardiac output decrease. So, major cardiovascular changes that occur in hypothyroidism includes: decrease in cardiac output decrease in cardiac contractility reduction in heart rate increase in peripheral vascular resistance Cardiovascular system

5. Fatigue Shortness of breathe Rhinitis Decrease exercise capacity This may result from impaired respiratory function as well as cardiovascular disease. Hypoventilation occurs because of respiratory muscle weakness and reduced pulmonary responses to hypoxia and hypercapnea. Respiratory system

6. Patients with hypothyroidism have a decrease in red blood cell mass and a normochromic and may have normocytic hypoproliferative anemia . Pernicious anemia occurs in 10% of patients with hypothyroidism caused by chronic autoimmune thyroditis . Hematology

7. Renal function: Decrease GFR Impaired ability to excrete water load. Neuromuscular system : Muscle cramps and weakness Paresthesias Carpal tunnel syndrome CNS: Lethargy, inability to concentrate, depression Effects of hypopthyroidism on other systems

8. Major symptoms and signs of hypothyroidism :

9. Primary Hypothyroidism Central Hypothyroidism Congenital Hypothyroidism Types of hypothyroidism:

10. Primary hypothyroidism is the gland itself is abnormal It is the most common type about 90%. Decreased T3,T4 and increased TSH. Central hypothyroidism: It is defined as hypothyroidism due to insufficient stimulation of thyroid gland by TSH : Secretion of TSH can be impaired at the hypothalamic or pituatory levels. ::: TSH is the most useful investigation of thyroid function for both hypo and hyperthyroidism Primary hypothyroidism:

11. Iodine deficiency Autoimmune thyroiditis Previous thyroidectomy Previous radio iodine treatment Previous external beam radiotherapy to the neck Drugs { Amiodarone, Lithium} Secondary hypothyroidism: Lesions compressing the pituatory like pituatory adenoma,craniophyrangioma and menningioma Primary hypothyroidism causes:

12. when iodine deficiency is more severe, thyroid harmone production falls and the patient may experience a hypothyroid condition. In such cases adults have the usual signs and symptoms of hypothyroidism and may lead to myxedema. However congenital hypothyroidism also known as cretinism fetus and young children prevents central nervous system development and maturation resulting in permenant mental retardation, neurologic defects and growth abnormalities. Iodine deficiency hypothyroidism

13. Severe iodine deficiency result in impaired thyroid harmone synthesis and thyroid enlargement {GOITER} Population effects of severe iodine dificiency termed as iodine dificiency disorders { IDDs } include: Endemic goiter Hypothyroidism Cretinism

14. A significant danger of iodine dificiency is maternal hypothyroidism leading to an insufficient supply of thyroid harmone to the fetus is entirely dependent on maternal thyroid harmone. Thus maternal hypothyroidism can produce a reduction in the IQ of the affected child. Maternal iodine dificiency will produce fetal iodine dificiency.

15. Drugs such as thionamides PTU inhibit the oxidation of iodine and subsequent binding of iodine to tyrosine residues in thyroglobulin. Lithium which is used in Tx of bipolar disorder, can induce hypothyroidism. The action of lithium appears similar to that high dose iodine inhibiting thyroid harmone release and organification of iodine. prolonged use of nitropruside may lead to hypothyroidism. Drug induced Hypothyroidism

16. Hashimoto thyroiditis is characterized by the destruction of thyroid cells by various cell and antibody-mediated immune processes. Patients with Hashimoto thyroiditis have antibodies to various thyroid antigens, ..anti-thyroid peroxidase { anti- TPO } .. antithyroglobulin { anti- Tg } ..TSH receptor-blocking antibodies { TBII } Autoimmune thyroid disease :

17. There is marked lymphocytic infiltration of the thyroid with germinal center formation, atrophy of the thyroid follicles , absence of colloid, and mild to moderate fibrosis. In atrophic thyroiditis , the fibrosis is much more extensive, lymphocyte infiltration is less pronounced, and thyroid follicles are almost completely absent. Atrophic thyroiditis likely represents the end stage of Hashimotos rather than distinct disorder. Pathogenesis:

18. In Hashimoto disaese destructive thyroiditis results from both cell mediated and humoral attack on the thyroid disease. The gland is typically enlarged but small and firm in early cases, with a palpable pyramidal lobe. Hyperthyroidism may transiently occur. But further gland damage rapidly leads to permenant hypothyroidism. Regression of goiter and the gland remnant will composed of fibrous tissue.

19. The process gradually reduces thyroid function. There is a phase of compensation when normal thyroid harmone levels are maintained by rised in TSH. Later, T4 levels fall and TSH level rises further. Symtoms become more readily apparent at this stage. which is referred to a clinical hypothyroidism or overt hypothyroidism.

20. Central hypothyroidism is defined as hypothyroidism due to insufficient stimulation of thyroid gland by TSH. Secretion of TSH can be impaired at the hypothylamic or pituatory levels. Central hypothyroidism

21. TUMOR HEMORRHAGE TRAUMA MALFORMATION POST-INFECTIOUS DAMAGE POST SURGICAL DAMAGE Causes of central hypothyroidism:

22. The term myxedema refers to the thickened, nonpitting edemetous changes to the soft tissues of patients in a markedly hypothyroid state. Myxedema coma is life threatening condition It occurs late in the progression of hypothyroidism The condition is seen typically in elderly women and is often precipitated by infection, medication, environmental exposure, or other metabolic-related stresses. Myxedema Coma

23. Symptoms can menifest in all organ system and range in severity based on the degree of harmone dificiency. The disease typically progresses over month to years. Onset of disease is quick following cessation of thyroid replacement medication or surgical removal of the thyroid gland.

24. Decrease mental ability cardiovascular collapse severe electrolyte imbalance cetrebral hypoxia { elevated CO2 levels } severe hypothermia. Coma If condition of hypothyroid progress lead to :

25. TFT Ultrasonography of neck Thyroid stimulating antibodies Biochemical changes: High triglycerides and high cholesterol Reduction in LDL receptors High creatinine level. Low plasma sodium Decrease Hb Investigations:

26. In most cases, hypothyroidism is treated by replacing the amount of hormone that your thyroid is no longer making . This is typically done with a medication. One medication that is commonly used is called levothyroxine . Taken orally, this medication increases the amount of thyroid hormone your body produces, evening out your levels. How hypothyroidism is treated?

27. Levothyroxine should be taken on an empty stomach with no other drugs or vitamins; multivitamins, including calcium and iron, can decrease its absorption. • If a patient has coronary heart disease that needs intervention, do the intervention (CABG or stent placement) before thyroid hormone replacement is initiated. Hypothyroidism is a manageable disease. However, you will need to continuously take medication to normalize the amount of hormones in your body for the rest of your life. With careful management, and follow-up appointments with your healthcare provider to make sure your treatment is working properly, you can lead a normal and healthy life.

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