Primary hypothyroidism is the most common cause of hypothyroidism, accounting for 99% of all cases.

TFT

1. THYROID FUNCTION TESTS &
ADRENAL FUNCTION TESTS

2. Thyroid function tests (TFTs)
The term ‘thyroid function tests‘ refers to the
followinginvestigations:
•TSH (0.4 –4 mU/L)
•Free T4 (9 –25 pmol/L)
•Free T3 (3.5 –7.8 nmol/L)
There are separate reference ranges for children
and pregnant women.

3.  Hypothyroidism
 Primary hypothyroidism
 Primary hypothyroidisminvolves reduced secretion of thyroid hormone from the thyroid gland itself.
 Pathology which decreases the thyroid’s ability to release T4 and T3 or respond to TSH can, therefore, cause primary
hypothyroidism.
 Primary hypothyroidism is themostcommoncause ofhypothyroidism, accounting for 99% of all cases.
 Pathophysiology
 1.Less T4 and T3 are produced due to the thyroid’s reduced capacity to produce hormone or respond to TSH.
 2.As a result, there is reduced negative feedback on the pituitary and hypothalamus.
 3.The reduction in negative feedback results in increased production of TRH (which we don’t typically measure) and
TSH.
 4.The end result is low T4 and T3 and a raised TSH.
 Diagnosis
 The typical findings that would indicate a diagnosis of primary hypothyroidism are as follows:
• Raised TSH:due to the absence of negative feedback.
• Low T4:due to the thyroid’s inability to produce enough T4.
 Anormal T4in the context of araised TSHmay suggestsubclinical hypothyroidism(most commonly caused by
underlying autoimmune disease).
 Aetiology

4. Causes ofprimaryhypothyroidisminclude:
•Autoimmune thyroiditis (50%)
•Iodine deficiency or excess
•Thyroidectomy
•Therapy with radioactive iodine –a treatment for
hyperthyroidism
•External radiotherapy
•Drugs
•Thyroid agenesis or dysgenesis

5.  Secondary hypothyroidism
 Secondary hypothyroidisminvolves a reduction in the hormones that stimulate the thyroid to produce thyroxine.
 Pathology which affects the pituitary and hypothalamic glands can result in decreased production of TRH and TSH, causing secondary
hypothyroidism.
 Secondary hypothyroidism is ararecauseofhypothyroidism, accounting for 1% of all cases.
 Pathophysiology
 1.Decreased production or secretion of TRH and TSH results in decreased stimulation of the thyroid gland.
 2.The thyroid gland, therefore, produces less T3 and T4.
 3.The low T3 and T4 would normally stimulate the pituitary and hypothalamic glands to increase TRH and TSH production, however,they are
unable to increase production.
 4.The end result is low T4 and T3 and a normal/low TSH.
 Diagnosis
 The typical findings that would indicate a diagnosis ofsecondaryhypothyroidismare as follows:
• Normal/low TSH:due to a lack of production.
• Low T4:due to the absence of any positive feedback from TSH.
 Aetiology
 Causes ofsecondaryhypothyroidismcan be eitherpituitaryorhypothalamicin origin.
 Pituitary causes:
• Pituitary adenoma: the most common cause.
• Pituitary surgery or radiotherapy which damages the pituitary tissue.
 Hypothalamic causes:
• Hypothalamic or suprasellar tumour.
• Surgery or radiotherapy which damages the hypothalamic tissue.
 TRH is not measured as part of thyroid function tests, as it is only released locally between the hypothalamus and pituitary (soit is not present
in representative quantities within the peripheral circulation). Both structures are commonly grouped together into ‘secondary’ because an
issue with TRH gives the same blood test results as an issue with TSH, however, some literature may refer to the hypothalamusasa ‘tertiary’
cause.

6. THYROID FUNCTION TESTS &
ADRENAL FUNCTION TESTS

7. Thyroid function tests (TFTs)
The term ‘thyroid function tests‘ refers to the
followinginvestigations:
•TSH (0.4 –4 mU/L)
•Free T4 (9 –25 pmol/L)
•Free T3 (3.5 –7.8 nmol/L)
There are separate reference ranges for children
and pregnant women.

8.  Hypothyroidism
 Primary hypothyroidism
 Primary hypothyroidisminvolves reduced secretion of thyroid hormone from the thyroid gland itself.
 Pathology which decreases the thyroid’s ability to release T4 and T3 or respond to TSH can, therefore, cause primary
hypothyroidism.
 Primary hypothyroidism is themostcommoncause ofhypothyroidism, accounting for 99% of all cases.
 Pathophysiology
 1.Less T4 and T3 are produced due to the thyroid’s reduced capacity to produce hormone or respond to TSH.
 2.As a result, there is reduced negative feedback on the pituitary and hypothalamus.
 3.The reduction in negative feedback results in increased production of TRH (which we don’t typically measure) and
TSH.
 4.The end result is low T4 and T3 and a raised TSH.
 Diagnosis
 The typical findings that would indicate a diagnosis of primary hypothyroidism are as follows:
• Raised TSH:due to the absence of negative feedback.
• Low T4:due to the thyroid’s inability to produce enough T4.
 Anormal T4in the context of araised TSHmay suggestsubclinical hypothyroidism(most commonly caused by
underlying autoimmune disease).
 Aetiology

9. Causes ofprimaryhypothyroidisminclude:
•Autoimmune thyroiditis (50%)
•Iodine deficiency or excess
•Thyroidectomy
•Therapy with radioactive iodine –a treatment for
hyperthyroidism
•External radiotherapy
•Drugs
•Thyroid agenesis or dysgenesis

10.  Secondary hypothyroidism
 Secondary hypothyroidisminvolves a reduction in the hormones that stimulate the thyroid to produce thyroxine.
 Pathology which affects the pituitary and hypothalamic glands can result in decreased production of TRH and TSH, causing secondary
hypothyroidism.
 Secondary hypothyroidism is ararecauseofhypothyroidism, accounting for 1% of all cases.
 Pathophysiology
 1.Decreased production or secretion of TRH and TSH results in decreased stimulation of the thyroid gland.
 2.The thyroid gland, therefore, produces less T3 and T4.
 3.The low T3 and T4 would normally stimulate the pituitary and hypothalamic glands to increase TRH and TSH production, however,they are
unable to increase production.
 4.The end result is low T4 and T3 and a normal/low TSH.
 Diagnosis
 The typical findings that would indicate a diagnosis ofsecondaryhypothyroidismare as follows:
• Normal/low TSH:due to a lack of production.
• Low T4:due to the absence of any positive feedback from TSH.
 Aetiology
 Causes ofsecondaryhypothyroidismcan be eitherpituitaryorhypothalamicin origin.
 Pituitary causes:
• Pituitary adenoma: the most common cause.
• Pituitary surgery or radiotherapy which damages the pituitary tissue.
 Hypothalamic causes:
• Hypothalamic or suprasellar tumour.
• Surgery or radiotherapy which damages the hypothalamic tissue.
 TRH is not measured as part of thyroid function tests, as it is only released locally between the hypothalamus and pituitary (soit is not present
in representative quantities within the peripheral circulation). Both structures are commonly grouped together into ‘secondary’ because an
issue with TRH gives the same blood test results as an issue with TSH, however, some literature may refer to the hypothalamusasa ‘tertiary’
cause.

11. Introduction
PowerPoint is a very commonly used,
fairly powerful presentation software from
Microsoft. In your academic career (undergrad,
graduate, or professional) there is a good
chance that you have been or will be exposed
to this tool. Furthermore, most of you will need
to use it. This slide show is intended not only to
be presented as a user guide to PowerPoint,
but to be distributed as a way to practice what
you learn as you learn it.

12. What Will be Demonstrated
Adding Slides to a Presentation
Using a Uniform Appearance/Motif
How to Vary Slide Layout and Text (font, size, color)
Using Graphics from ClipArt or a File
Using Animated Text (Timed and Manual)
Applying Slide Transitions
Adding Sound (From a File or the Gallery)
Using AutoShapes
Adding Videos and Animation
Placing Action Buttons for Nonlinear Slide Selection
Linking to Web Content or Email Addresses

13. Adding/Formatting Slides
Right-Click the Timeline to the left and go
to “New Slide”
OR go to “Insert” and select “New Slide”
Open the “Layout” tab to the right to
change the format of a slide

14. Appearance/Motif
You can Apply a Motif by Opening the
“Design” tab on the right 
–Then Click on the Desired Motif to apply it to all
slides
–Click on the small drop down if you wish to apply
the motif to only the current slide

15. Variation in Layout and Text
To Select a New Slide
Layout, Open the
“Layout” Tab to the
right 
You can Use the Font
Color drop down menu
to change the text color
Use the Drop Down
Fontand Size
menus above to vary
the text

16. Clip Art Graphics
To Insert ClipArt, go to “Insert” and put your
mouse on “Picture”
Another Menu will Open, select ClipArt
Once you Select your Image, You must
Position and Resize it with the Mouse

17. File Graphics
To Insert a File Image, go to “Insert” and put
your mouse on “Picture”
Another Menu will Open, select “From File”
Once you Select your Image, You must
Position and Resize it with the Mouse

18. Animated Text (Manual)
1) Set Up your Slide the Way You Want
2) Go to “Slide Show”
–and select “Custom Animation”