Who it affects
Hyperthyroidism is also known as thyrotoxicosis or an over active
thyroid and is a relatively common disorder. An over active thyroid may result from
various causes. Patients with Graves disease are usually younger,
female and may have a history or family history of diseases such as
rheumatoid arthritis, pernicious anaemia or Addison`s disease. Multiple
benign overactive thyroid nodules is another cause. This is called a
toxic multi-nodular goitre. More rarely an overactive thyroid can be due
to drugs such as Amiodarone or a single hyperactive thyroid nodule
(toxic nodule). Postpartum thyroiditis refers to abnormal thyroid
function following the delivery of a child.
What gland is involved
The thyroid gland lies in the front part of the neck just under skin and
below the thyroid cartilage (Adam`s apple).
Hyperthyroidism may cause symptoms such as weight loss, increased
appetite, tremor of the hands, palpitations, loose motions or menstrual
The blood tests used to diagnose an overactive thyroid are Thyroid
Stimulating Hormone (TSH), free T4 and sometimes free T3. Free T4 is
produced by the thyroid in response to TSH stimulation. Free T4 is
converted to free T3, the more active form of the hormone. TSH is
produced by the pituitary and because of thyroid hormone feedback,
levels are low or undetectable in hyperthyroidism. The tests used to
determine what caused thyroid over activity may include blood tests
(thyroid anti-bodies), ultrasound scans or thyroid isotopes scans.
The treatment of an overactive thyroid is dependent on the cause.
Graves` disease is typically treated with anti-thyroid medication (Carbimazole
or Propylthiouracil) for 6-18 months. Once discontinued, about 50% of
patients may remain off medication. In those whom an over active thyroid
re-occurs (relapse), treatment with radioiodine or surgery may be
Anti-thyroid medication may be titrated to control thyroid function or
used in a "block and replace" fashion. Block and replace therapy entails
using anti-thyroid medication to block thyroid hormone production and
levothyroxine replacement to normalise TFTs.
Hyperthyroidism due to a multinodular goitre is usually treated with
radioiodine or surgery, although medication is usually prescribed
About half of patients with Graves` disease are able to successfully
discontinue all medication after a closely monitored course of
Patients treated with surgery (total thyroidectomy) or radioiodine
(ablative doses) usually become hypothyroid and require lifelong
Thyroid surgery is arranged by referring to a surgeon.
Surgical removal of the entire thyroid gland will result in
hypothyroidism and require lifelong levothyroxine therapy. The
parathyroid glands lie behind the thyroid and although efforts are made
to avoid it, these may also be removed during total thyroidectomy
surgery. Such patients may require lifelong vitamin D therapy.
Some surgeons aim to achieve normal thyroid function off medication by
removing part of the thyroid gland. With this approach, there is however
a chance that the thyroid remains overactive or becomes overactive at a
Radioiodine is a popular alternative to surgery. It involves the
administration of the isotope I131 that is administered in the form of a
liquid or tablet. Patient will be advised to take certain precautions
e.g. avoiding contact with young children and pregnant women for a
period of time after treatment. The main side-effect of radioiodine
therapy (ablative dose) is to render the patient`s thyroid under active.
Life-long levothyroxine therapy is required in this case. It is
important that if you are considering radioiodine therapy, you mention
to your endocrinology specialist if:
1. you come into contact with children or pregnant women
2. you suffer from urinary incontinence
3. plan to conceive
4. you are a carer for someone
Dr A Qureshi
is a consultant endocrinologist and diabetologist who consults at The
Harley Street Clinic, London, UK. He specialises in disorders such as
hypothyroidism, hyperthyroidism, hyperparathyroidism, hypopituitarism,
Addison’s disease, hypertension and diabetes.
To arrange an appointment, please call:
APPOINTMENTS : ++44 (0)7733
The information contained in this website is general and not specific
endocrine or diabetes advice.
Patients should always consultant their physician or an endocrinology
specialist. For further details please read the full disclaimer.