Hypothyroidism

Question 1

Hypothyroidism

Answer 1

lack of thyroid hormones

• Decreased basal metabolic rate

Question 2

Primary hypothyroidism

Answer 2

Thyroid gland is not making enough thyroid hormone

• Increased level of TSH to stimulate gland

• > Stimulates fibroblasts in skin and soft tissue
• > stimulated fibroblasts start depositing glycosaminoglycans (extracellularmatrix proteins) into interstitium

Question 3

Causes of primary hypothyroidism

Answer 3

1. Iodine deficiency
2. Hashimoto Thyroiditis - (autoimmune disorder)
   - T cells and
   - anti-thyroid peroxidase
   - antithyroglobulin antibodies
   Infiltrate the thyroid
   • Damage thyroid and increase in TSH leads to thyroid hypertrophy and hyperplasia
   • Responds to autoimmune attack by enlarges
   • Overtime destroys thyroid function all togather
3. Resection of thyroid gland/ radiation damages follicular cells for hyperthyroidism treatment
4. Congenital hypothyroidism - mainly sporadic and caused by inherited genetic mutation
   • defect in thyroid gland development or function

Question 4

Secondary Hypothyroidism (central hypothyroidism)

Answer 4

• body doesn’t produce enought TSH
1. Tumor in anterior pituitary
• Compresses gland and prevents TSH production
2. Damage to hypothalamus
• Tumor/trauma
• Decrease in thyrotropin releasing hormone production

Question 5

Symptoms of hypometabolism

Answer 5

1. Weight gain despite loss of appetitite - decrease in bsal metabolic rate
2. Cold sensitivity as body is producing less heat

(decreased effect of thyroid hormone on sympathetic nervous system)

3. Slower heart rate
4. Mental slowness
5. Lethargy
6. Constipation
7. Accumulation of glycosaminoglycans ->Myxedema -> swelling of skin and soft tissues
8. Hashimoto thyroiditis -. Goiter
9. Congenital hypothyroidism -> reduced metabolic rate
   • excessive sleeping//mental retardation//intellectual disabilities

Question 6

Myxedema Coma

Answer 6

• affects people with poorly managed hypothyroidism who undergo stressful situation
  e. g. infection or surgery
• heightened symptoms of hypothyroidism
• mental slowness -> altered consciousness and confusion
• decreased body temp -> hypothermia

Question 7

Diagnosis

Answer 7

• measuring blood levels of tsh, t3 and t4
- Thyroid hormones will be low but TSH vary
• Primary cause -> TSH will be high
• Secondary cause -> TSH will be low or normal

Question 8

Treatment for all types

Answer 8

1. Thyroid hormone replacement therapy - use of synthetic T4