Thyroid disease Flashcards
CLINICAL APPLICATION
Tips for examining the thyroid?
- Low in neck, feel for thyroid cartilage (adams apple in m) then inferior and laterally
- Moves on swallowing
- Listen for bruit
- Retrosternal extension?
! Always check cervical lymph nodes
CLINICAL APPLICATION
Which thyroid function tests are available?
Advantage and disadvantage of measuring TSH?
- TSH
- Free T3/T4 (FT3/FT4)
- Thyroid antibodies e.g. Anti-TPO AB, TRAB-TSH receptor auntoantibody
Good at testing thyroid function
TSH is slow to respond to change (approx 6 weeks) and assumes normal pituitary function
How does the prevalence of autoAB correlate to disease states?
High prevalence of autoAB in autoimmune disease
- Many are sequestered/ intracellular
! A negative autoAB doesnt mean its not an autoimmune disease
What types of thyroid autoimmune disease exists?
‘destructive’ - target thyroid AI destruction
‘stimulatory’ - stimulate TSH receptor
State 5 common symptoms of hypothyroidism
- Heavy menstruation
- Asymptomatic
- Lethargy
- Mild weight gain
- Cold intolerance
- Constipation
State 5 common symptoms of SEVERE hypothyroidism
- Goitre
- Carpal tunnel
- Effusions
- Bradycardia
- Stupor/coma
- Facial puffiness
- Flaking dry skin
- Diffuse hair loss
- Hoarseness
State 3 primary causes of hypothyroidism
Give a secondary cause
- Autoimmune hypothyroidism
- Hypothyroidism after treatment for hyper (Iatrogenic)
- Thyroiditis
- Drugs (lithium, amiodarone)
- Congenital
6 Iodine deficiency (not applicable to UK)
Disease of the hypothalamus or pituitary gland
CLINICAL APPLICATION
What investigation would be appropriate for suspected hypothyroidism?
Blood serum
Thyroid autoantibodies?
No imaging necessary
CLINICAL APPLICATION
Standard treatment for hypothyroidism?
Start: Thyroxine (T4) 100ug daily
- shorter symptomatic period
- in elderly/IHD start with 25ug and increase in increments over 4-6 weeks
Aim: normal FT4 without TSH suppression
**normal is different/person
State 5 symptoms of hyperthyroidism
- Loose bowel
- Weight loss (with increased appetite)
- Lack of energy
- Heat intolerance
- Anxiety/ irritability
- Oligomenorrhoea
- Increased sweating
- Increased thirst
- Palpitations
- Pruritis (itch)
- Weight gain
State 5 signs of hyperthyroidism
- Tremor
- Warm, most skin
- Tachycardia
- Brisk reflexes
- Thyroid bruit
- Muscle weakness
- Atrial fibrillation
- EYE SIGNS (TED/TAO)
In which condition do 20% of patients show eye signs like those in hyperthyroidism?
What causes these?
State 5 symptoms of TED/TAO?
What investigation might be useful here?
Graves (increased in smoking patients)
Autoantibody mediated, inflammation of orbital tissues (fat, muscle, conjunctivae, eyelids) except eyes itself
- Itchy/dry
- ‘Prominent’ eyes
- Diplopia/ loss of sight
- Loss of colour vision
- Redness/swelling of conjunctiva
- Unable to close eyes fully
- Ache/pain/tightness in/behind eye
CT, especially if “worrying” symptoms (last 5)
Graves is a common cause of hyperthyroidism. Comment on its epidemiology and mechanism of disease
State 5 other causes of hyperthyroidism
Graves accounts for 75% of cases, mainly women aged 30-50. Autoantibody stimulates the TSH receptor, causing excess TH production and goitre
- Toxic multinodular goitre
- Toxic adenoma
- Thyroiditis
- Drugs e.g. amiodarone
- Gestational
Comment more on gestational hyperthyroidism
- placental b-human chronic gonadotrophin is structurally similar to TSH and TSH- like action on the thyroid
- increased likelihood is hyperemesis (twin pregnancy)
- settles after first trimester
CLINICAL APPLICATION
What investigations might suggest a diagnosis of Graves?
If Graves:
- FHx of automimmue thyroid/endocrine disease
- Goitre with bruit
- Thyroid eye disease (20%)
- Positive thyroid autoantibody titre
- TSH-receptor autoantibodies (graves)
