Thyroid: Hypothyroidism Flashcards
(16 cards)
What is hypothyroidism?
Insufficient T3 and T4 production
T3 and T4 are thyroid hormones crucial for metabolism.
What characterizes primary hypothyroidism?
Abnormal thyroid produces inadequate hormones with LOW T3 and T4, TSH is HIGH with -ve feedback
The negative feedback mechanism involves the inhibition of TSH production due to high T3 and T4 levels.
What is the most common cause of primary hypothyroidism in the developed world?
Hashimoto’s thyroiditis
An autoimmune condition causing thyroid inflammation.
What antibodies are associated with Hashimoto’s thyroiditis?
Anti-TPO and anti-Tg antibodies
These antibodies are markers for autoimmune thyroid disease.
What is the most common cause of primary hypothyroidism in the developing world?
Iodine deficiency
Iodine is essential for the production of thyroid hormones.
What is a treatment option for hyperthyroidism?
Carbimazole
Carbimazole is an antithyroid medication that reduces hormone production.
What effect does lithium have on thyroid hormones?
Inhibits thyroid hormones production, causing goitre
Goitre is an enlargement of the thyroid gland.
What is the impact of amiodarone on thyroid function?
Interferes with hormone production and metabolism, causing hypothyroidism and thyrotoxicosis
Amiodarone is a medication used for heart rhythm disorders.
What characterizes secondary hypothyroidism?
Abnormal pituitary produces inadequate TSH, under activation of thyroid causing LOW T3 and T4
This condition is due to problems with the pituitary gland.
What is a common cause of secondary hypothyroidism?
Hypopituitarism
This condition involves a deficiency of one or more pituitary hormones.
What are potential causes of hypopituitarism?
- Tumours (e.g., pituitary adenomas)
- Surgery to the pituitary
- Radiotherapy
- Sheehan’s syndrome
- Trauma
Sheehan’s syndrome is related to severe blood loss during or after childbirth.
List some common symptoms of hypothyroidism
- Weight gain
- Fatigue
- Dry skin
- Coarse hair and hair loss
- Fluid retention
- Heavy or irregular periods
- Constipation
- Goitre
Fluid retention can include oedema, pleural effusions, and ascites.
What is the first-line treatment for hypothyroidism?
Oral Levothyroxine
Levothyroxine is a synthetic version of T4.
How is the dose of Levothyroxine adjusted?
Titrated based on TSH levels every 4 weeks
Regular monitoring of TSH is essential for optimal dosing.
What is the second-line treatment for hypothyroidism?
Liothyronine Sodium
This is a synthetic version of T3, used only if the first line is not tolerated.
Liothyronine Sodium is used under what condition?
ONLY if 1st line not tolerated
It should be managed under specialist care.
