10. Primary –
autoimmune – hashimotos thyroiditis,atrophic thyroiditis
Iatrogenic;I131 treatment ,subtotal or total thyroidectomy; external irradiation of
neck for lymphoma or cancer
Drugs-iodine excess(including iodine containing contrast media and
amiodarone)lithium ,antithyroid drug,p-amino salisalic acid,interferon alpha
Congenital hypothyroidism-absenteectopicthyroid,dyshormonogenesis,tsh-r
mutation iodine defieciency
Infiltrative disorder-amylodosis,sarcoidosis,
hemochromatosis,scleroderma,cystinosis, riedels thyroiditis
Transient-
silent thyriditis,including post partum thyroididtis
Subacute thyroiditis
Withdrawl of thyroid treatment in indiviual with intact thyroid
Secondary-
hypopituitarism:tumour ,pituatry surgery or irradiation,infiltrative disorder,sheehans
syndrome,trauma,genetic form of combined pituatryhormone deficiencies
Isolated Tsh deficiency or inactivity
Bexaretone treatment
13. Cool and pale skin blood flow
Dry roughness of skin the epidermis has an
atrophied cellular layer and hyperkeratosis
Decreased sweating calorigenesis and acinar
gland secretion
Generalized nonpitting edema (myxedema) in
severe hypothyroidism infiltration of the
skin with glycosaminoglycans and associated
water retention
14. Periorbital edema -- as a manifestation of
generalized nonpitting edema or Graves'
ophthalmopathy.
Graves' ophthalmopathy may persist or
worsen when hypothyroidism develops
after treatment of Graves' hyperthyroidism.
Patients will have variable degrees of stare,
protrusion of the eyes, and extraocular
muscle weakness.
15. Bradycardia reductions in heart rate
Impaired muscular contractility
Reduced cardiac output decreased exercise capacity
and shortness of breath during exercise
ECG: low voltage of QRS complexes and P and T
waves
CXR: cardiomegaly interstitial edema, myofibrillary
swelling, LV dilatation, pericardial effusion
16. Myxedema induces coronary artery disease ??
CAD more common in p’ts with
hypothyroidism
Symptoms and signs of congestive heart
failure are usually absent in patients who
have no other cardiac disease
Congestive heart failure or angina may
worsen when hypothyroidism develops in
patients with heart disease
17. Hypertension peripheral vascular
resistance
In normotensive patients, BP increases are small
(<150/100 mmHg).
The BP of patients with established hypertension
may increase further with the development of
hypothyroidism.
18. Constipation, even ileus gut motility
Decreased taste sensation
Gastric atrophy presence of antiparietal cell
antibodies. Pernicious anemia occurs in 10% of
patients with hypothyroidism caused by chronic
autoimmune thyroiditis.
Weight gain decreased metabolic rate +
accumulation of fluid (nonpitting edema) that is
rich in glycosaminoglycans
Ascites, rare
19. General depression of central nervous system
function
Sleepiness, inability to concentrate
Sluggish thought processes
Respond slowly to questions
Less able to retrieve information from memory
Agitated psychosis, rare (“myxedema madness”)
PET: 23% reduction in cerebral blood flow and a
12% reduction in cerebral glucose metabolism
20. A delay in the relaxation phase of deep
tendon reflexes
Carpal tunnel syndrome
Paresthesia
Asymptomatic elevation in serum CPK level
to muscle hypertrophy (which may be
accompanied by muscle cramps) to
proximal muscle weakness to, in rare cases,
rhabdomyolysis.
21. Hyponatremia may result from a reduction in free
water clearance
Reversible increases in serum creatinine occur in 20
~ 90% of hypothyroid patients
lipid clearance may be decreased, resulting in an
elevation in the serum concentrations of free fatty
acids and total and low-density lipoprotein
cholesterol
Plasma homocysteine concentrations are increased
in some hypothyroid patients,
22. Fatigue, shortness of breath on exertion, and
decreased exercise capacity impaired
respiratory function + cardiovascular disease
Hypoventilation (shallow and slow
respirations) respiratory muscle weakness
+ reduced pulmonary responses to hypoxia
and hypercapnia
Obstructive sleep apnea macroglossia
23. Decreased glomerular filtration rate (GFR )
Impaired ability to excrete a water load
The drug clearance (ex, antiepileptic,
anticoagulant, hypnotic and opioid drugs), is
decreased. Drug toxicity may occur if drug
dosage is not reduced.
During T4 replacement, drugs that are
administered at effective doses in patients who
are hypothyroid may become less effective.
24. Impaired hemoglobin synthesis thyroxine
deficiency
Iron deficiency increased iron loss with
menorrhagia + impaired intestinal absorption
of iron
Folate deficiency impaired intestinal
absorption of folic acid
Pernicious anemia vitamin B12-deficient
megaloblastic anemia
25. Women with hypothyroidism may have either oligo-
or amenorrhea or hypermenorrhea-menorrhagia.
Decreased fertility
Increased likelihood for early abortion
Hyperprolactinemia may occur, and is occasionally
sufficiently severe to cause amenorrhea or
galactorrhea
The serum sex hormone-binding globulin
concentration may be low in hypothyroidism. This
will lower serum total but not free sex hormone
concentrations.
26.
27. features Primary secondary
skin Thick and
without
wrinkle
Thick with fine
wrinkle
Hair coarse fine
Menstrual
irregularities
menorrhagia amenorrhea
Secondary
sexual changes
Normal poor
Heart size May be
enlarged
small
Goitre May be present absent
Soft tissue
edema
Marked absent
Blood pressure Normal or high low
cholestrol increased normal
TSH high low
28. Chronic lymphocytic thyroiditis
Probably the most common cause of
hypothyroidism
With (younger patients) or without goiter (older
patients – atrophy gland after destruction by
immunologic process)
High titer of autoantibodies to thyroidal
antigens (Thyroglobulin Ab,
Thyroperoxidase Ab = TPO Ab =
Antimicrosomal Ab = AMA)
