GPST2 - Oct 2010
90% of cases are due to:
toxic nodular goitre:
single toxic nodule - usually an adenoma
Other common causes:
silent / post-partum
Hashimoto's - hashitoxicosis may develop mid-course
intentional / factitious
Jod - Basedow
transient - neonatal
Hyperthyroidism as a result of pathology in another organ
which causes excess stimulation of the thyroid gland.
TSH secreting pituitary adenoma
pituitary stimulation due to excessive hypothalamic release of
embryonal testicular carcinoma
Extraneous thyroid hormone - all rare:
struma ovarii - ovarian teratoma with thyroid tissue
metastatic, well differentiated thyroid carcinoma
differentiation may be difficult clinically
positive findings for thyrotoxicosis are eye signs,
proximal myopathy, wasting, hyperdynamic circulation
with warm peripheries
anxiety tends to cause clammy hands
especially if the patient is hypertensive
T3 and T4 determination
TSH determination - normal serum TSH concentration nearly always
excludes the diagnosis of thyrotoxicosis; the rare exceptions to
this are a TSH-producing pituitary tumour or thyroid hormone
TRH stimulation test (rarely performed)
radioisotope iodine scanning
normochromic normocytic anaemia may be
seen in Graves' disease
raised in Graves' disease
high in subacute thyroiditis
Calcium - often raised
LFTs - may be abnormal in Graves' disease
Admit if the person has severe signs and symptoms of
hyperthyroidism (e.g. fever, agitation, heart failure,
confusion, or coma) or is systemically unwell.
Otherwise, refer all other individuals with overt
hyperthyroidism for specialist management. The need
for treatment should be based on the degree of
elevation of serum free thyroxine (FT4) and free
triiodothyronine (FT3) and clinical symptoms and signs
as well as the cause of hyperthyroidism:
The decision to initiate treatment with a thionamide
(carbimazole or propylthiouracil) in primary care
should be made under specialist advice.
Consider a beta-blocker for symptomatic treatment or
if a contraindicated, seek specialist advice regarding
alternative drug treatment (e.g. diltiazem).
chronic autoimmune thyroiditis
following thyroidectomy or radioiodine treatment
iodine deficiency or, rarely, gross excess
de Quervain's thyroiditis - usually transient
silent thyroiditis - usually transient; may be permanent
post-external beam irradiation to the neck
Uncommon and is usually caused by:
hypothalamic lesion with isolated TSH deficiency
Treat overt hypothyroidism with
All people who are stable on levothyroxine
require at least annual measurement of
serum thyroid-stimulating hormone (TSH):
To check compliance
To ensure that the dosage is still correct
Aim to achieve a serum thyroid-stimulating hormone
(TSH) concentration that is within the reference
range (0.4–4.5 mU/L).
In the elderly, younger people and those with IHD
start with small dose (25-50mcg) and titrate at 2-3
month intervals with 25-50mcg steps
Measure TSH and free thyroxine (FT4) 2–3 months
after each change in dose of levothyroxine.
Most people have a normal serum TSH
concentration on a maintenance dose of 75–150
micrograms of levothyroxine daily.
When to refer- Hypothyroidism
Secondary hypothyroidism is suspected (refer urgently).
Subacute Thyroiditis(de Quervain's thyroiditis) is suspected.
Hypothyroidism is thought to be due toend organ
They are younger than 16 years of age.
They are pregnant or postpartum.
They have particular management problems (e.g.
ischaemic heart disease, or being treated with
amiodarone or lithium).
They feel worse during treatment, as they may have
undiagnosed adrenal disease.
They have continuing symptoms after appropriate
thyroxine treatment (i.e. thyroid function tests are now
within the reference ranges) to investigate for a non-
thyroid cause of the symptoms
Case study 1
72 year old living independently and rarely comes to the
doctors. She had lost her purse on three occasions within
the last fortnight and her son had arrived for his monthly
visit on Monday to find she thought it was a Sunday and
was upset that her cat was missing (the cat had died 2 years
He has brought her to you today. The patient appears upset
in surgery that due to a misunderstanding she has had to
miss church and come to the surgery. She is apologetic for
using up your spare time. Her main complaint is her eyes
which feel sore and watery and she says she is getting
breathless going up the stairs.
On examination she has a pulse of 90 which
is irregular. She has sparse bibasal creps on
auscultation of the chest. Her urine dip is
negative and the remainder of the
examination is unremarkeable. Her eyes are
reddened. Her BMI is 18 and you notice
that her wedding ring is loose on her finger.
BP is 180/100
The son is ok to stay with her for a fortnight
and neither are keen for a hospital admission.
Thyroid function tests come back within the
T4 27, TSH 0.01.
She is given:
Carbimazole 20mg od (pt has low BMI)
Lubricating eye drops
Refer to endocrinologist
Son wants to know how long it will take for
mother to be able to be left alone again.
Son asks about side effects of ‘toxic’
In the older population, thyroid disease can
present in different ways – confusion which
is not acute in onset and vague
constitutional symptoms. In any acute
confusional state it is reasonable that if you
do not have an obvious cause, to do thyroid
Thyroid eye disease (exclusive to Grave’s disease)
leaves patients with sore watery eyes and can be
severe enough to restrict the eye movements and
cause discomfort with eye movements. This may
be helped with a course of high dose steroids and
may require surgery but in less severe cases, a
bottle of hypromellose is all that is required to
Case Study 2
36 yr old, presents with palpitations, lethargy and
sore throat , worse on swallowing for 2 days. This
was preceded by a cold with a cough but she feels
she is getting worse and now getting hot and cold
sweats. Routine examination reveals no
abnormality in the ears, nose or throat and mild
pyrexia of 37.9.
What else would you check?
Neck glands…… Tender anterior neck,
worse on swallowing. There is no palpable
Pulse…… Rate 110 ?related to fever
deQuervains thryroiditis – uncommon post viral
inflammation of thyroid gland. There may or may
not be a palpable goitre but the thyroid gland will
be tender. The patient will have symptoms of
hyperthyroidism at the outset and this is
accompanied by a pyrexia.
The condition is self limiting (within months) and
usually follows course of hyperthyroidism,
hypothyroidism then euthyroidism. Due to viral
cause, no antibiotics are indicated and treatment
options include NSAIDs, prednisolone and beta
blockers for symptom control.
Refer endocrinologist for monitoring.
Case Study 3
9 year old boy with lump in the neck approx pea
sized. Non tender. No other symptoms.
On examination lump is on left side of thyroid gland
b. Check TFTs?
c. Arrange ultrasound and fine needle aspiration
d. Refer to Thyroid surgeon?
Answer is d. This patient fulfils the 2-week
urgent cancer referral for head and neck.
A Thyroid swelling associated with any
one of the following:
A solitary nodule increasing in size
A history of neck irradiation
A family history of an endocrine
Unexplained hoarseness or voice
Very young (pre-pubertal) patient
Patient aged 65 years and older
The reason why you do no other tests before
referral is that this may cause unnecessary
delay to the patient’s diagnosis and
treatment. Once the 2-week rule cancer
referral has been received the department
can organise any scans or tests much faster
than you would be able to in primary care.