Hypothyroidism is caused by low levels of thyroid hormones and can be primary or secondary. It can occur at any age but presents differently in infants (cretinism) and adults (myxedema). Cretinism results from congenital lack of the thyroid gland and is characterized by stunted growth and mental retardation. Untreated congenital hypothyroidism permanently impairs development. Myxedema in adults slows metabolism and causes non-pitting edema. Hypothyroidism is typically treated with daily levothyroxine replacement therapy to normalize thyroid stimulating hormone levels. Early diagnosis and treatment of congenital hypothyroidism is important for normal mental development.

1. E G BHARATHVAASAN
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2. Thyroid hormone increases
the metabolism and protein
synthesis in almost all body
tissues.
It is also necessary for brain
development and growth in
infants for 6 months

3. Hypothyroidism is a clinical syndrome
caused by low levels of circulating thyroid
hormones.
Aetiology
Depending upon the aetiology,
hypothyroidism
1. Primary hypothyroidism
2. Secondary hypothyroidism

4. Depending upon age where the deficiency and
severity of disease it is of two types
 1.INFANTILE HYPOTHYRODISM
 2. ADULT HYPOTHYROIDISM

5. It is also known as infantile
hypothyroidism
Cretinism is caused by extreme
hypothyroidism during fetal life,
infancy, or childhood. This condition is
characterized especially by failure of
body growth and by mental retardation.
It results from congenital lack of a
thyroid gland –congenital Cretinism

6. From failure of the thyroid gland to
produce thyroid hormone because of
a genetic defect of the gland, or
from iodine lack in the diet endemic
cretinism.
The severity of endemic cretinism
varies greatly, depending on the
amount of iodine in the diet

7. Antithyroid drugs Carbimazole and
methimazole can easily cross the
placenta and block the fetal thyroid
function
THYROIDITIS: it is an autoimmune
disorder
Untreated congenital
hypothyroidism impairs body growth
and mental retardation

8. cretinism

9.  Myxedema develops in the patient with
almost total lack of thyroid hormone
function.
 Hypothyroidism in adults causes the
Myxedema
 Slow the metabolic process
 Non pitting edema
 It is normal and few sign and symptoms
 Myedematous coma is life threating.

10. greatly increased quantities of
hyaluronic acid and chondroitin sulfate
bound with protein form excessive
tissue gel in the interstitial spaces, and
this causes the total quantity of
interstitial fluid to increase
Because of this gel nature of the
excess fluid, it is mainly immobile and
the edema is the nonpitting type

13.  Thyriodectomy
 Lithium bicarbonate
 Carbimazole and methimazole
 Amiodarone

14. Investigations Serum T3 and T4 levels low
 Serum TSH levels high in primary and low in
secondary hypothyroidism
 Serum cholesterol high
 Peripheral blood smear- macrocytic anaemia
 Photomotogram-delayed ankle jerk

15. GENERAL FEATURES
CARDIOVASCULAR FEATURES
NEUROLOGICAL FEATURES
DERMATOLOGICAL FEATURES
REPRODUCTIVE FEATURES
GASTROINTESTINAL
HEAMOTOLOGICAL FEATURES

16.  Treatment must be started in first 2
weeks of life to prevent brain
damage
Consequently, it is easy to maintain a
steady level of thyroid hormone activity
in the body by daily oral ingestion of a
tablet or more containing thyroxine.

17. Replacement of thyroid hormone
with oral levothyroxine
The dose is treated until the TSH
levels are normol in the circulation
If the TSH level is high then
levothyroxine is too low and need to
be increased until balances with
normal and viceversa

18. Hypothyroidism is most important
preventable cause of mental and
intellectual handicap
 Iodine deficiency is most important
preventable cause of
Hypothyroidism
Early diagnosis and treatment after
birth is important for normal mental
development