5. Hypothyroidism
Definition
Causes of hypothyroidism
Clinical manifestations of hypothyroidism
Laboratory evaluation
Autoimmune hypothyroidism
6. Definition
The thyroid gland produce 2 related hormones,
thyroxine (T4) and triiodothyronine(T3)
These hormones help to maintain thermogenic and
metabolic homeostasis in the adult.
Hypothyroidism results specially from glandular
destruction and underproduction of thyroid
hormones.
9. Causes of hypothyroidism
Transient hypothyroidism:
Silent thyroiditis , including postpartum thyroidtis
Subacute thyroiditis
Withdrawal of thyroxine trt
10. Causes of hypothyroidism
Secondary hypothyroidism:
Hypopituitarism: tumors, pituitary surgery or
irradiation, infiltrative disorders, Sheehan’s syndrome,
trauma
Hypothalamic disease: tumors, trauma, infiltrative
disorders , idiopathic
14. Laboratory evaluation
Dyslipidemia with elevated cholesterol and
triglycerides
Anemia
TSH ↑ and FT4 nle: subclinical hypothyroidism
TSH ↑ and FT4↓:clinical hypothyroidism
TSH nle or ↓ and FT4 ↓:secondary hypothyroidism
15. Autoimmune hypothyroidism
Autoimmune hypothyroidism may be associated with
a goiter (Hashimoto’s disease) or ,at the later stages of
the disease, minimal residual thyroid tissue (atrophic
thyroiditis)
First preceded by subclinical hypothyroidism with
normal thyroid hormones levels and elevated TSH
Later ,FT4 levels fall and TSH levels rise further
Female >male
Anti TPO +++