It is a clinical syndrome that results from exposure of the body tissues to excess circulating levels of free thyroid hormones.
It is five times more common in females.
1 . Grave’s disease – 76%
2. Multinodular goitre – 14%
3. Autonomously functioning solitary thyroid nodule – 5%
4. Thyroiditis
1. Subacute 3%
2. Postpartum
5. Drugs: amiodarone
Hyperthyroidism develops usually insidiously and most patients have had symptoms for at least 6
months before presentation.
This is the most common cause of hyperthyroidism and is an autoimmune process in which serum IgG antibodies bind to the thyroid TSH receptors and produce stimulation of thyroid hormone production, behaving like TSH.
These antibodies are called thyroid-stimulating antibodies (TSAB).
Most patients belong to the age group 30-50 years.
Grave’s disease is distinguished clinically from other causes of hyperthyroidism by the presence of:
1- Diffuse thyroid enlargement (thyroid goiter)
2- Ophthalmopathy (eye changes)
3- Peritibial myxoedema (rare)
1. Nervousness, irritability, tremor
2. Palpitation, dyspnea or exertion, angina
3. Weight loss, diarrhea
4. Increased sweating
5. Amenorrhea/impotence
6. Lid retraction and other* eye/ symptoms in Grave*s
disease.
Diffuse + bruit
Nodular
Weight loss despite normal or increased appetite
Diarrhea and steatorrhoea
Anorexia
Vomiting
Palpitations, sinus tachycardia, atrial fibrillation
Increased pulse pressure
Ankle oedema in absence of cardiac failure
Angina, cardiomyopathy, and cardiac failure
Dyspnoea on exertion
Exacerbation of asthma
Hyperthyroid facies
Warm and sweaty palms
Tremor
Onycholysis (separation of the distal end of the nail) is also called Plummer’s nail.
Clubbing and swelling of fingers.
Pulse: tachycardia
Irregular pulse due to atrial fibrillation, high volume collapsing pulse.
Proximal myopathy.
Brisk reflexes
Nervousness
Irritability
Emotional lability
Psychosis
Tremor
Hyperreflexia, ill-sustained clonus
Muscle weakness
Proximal myopathy, bulbar myopathy
Periodic paralysis
Increased sweating
Pruritus
Palmar erythema, spider navi
Onycholysis
Alopecia
Pigmentation, vitiligo
Digital clubbing
Peritibial myxoedema
Amenorrhoea/oligomenorrhoea
Infertility
Spontaneous abortion
Loss of libido, impotence
Exophthalmos: sclera visible below cornea.
Lid retraction: sclera visible above cornea
Conjunctiva: chemosis
Lid lag: ask the patient to follow your finger descending at a moderate rate.
The eye movements for ophthalmoplegia
Examine fundi for optic atrophy
Proptosis: look from behind and above.
Look for thyroid enlargement
Scar of surgery
Palpate thyroid
Auscultate for bruit
On raising the arm above the head, patients with retrosternal goiter may develop signs of compression such as
congestion of face raised JVP, and inspiratory stridor.
# Lid retraction, lid lag
# Grittiness, excessive lacrimation
# Chemosis
# Exophalmos, corneal ulceration
# Ophthalmoplegia, diplopia
# Papilloedema, loss of visual acuity
Heat intolerance
Fatigue, apathy
Lymphadenopathy
Thirst
Osteoporosis
Gynaecomastia in males
Ejection systolic murmur
Signs of cardiac failure
Pretibia myxedema
Hyperreflexia
Atrial fibrillation
Periodic paralysis
Hypercalcemia and nephrocalcinosis.
Osteoporosis
Decreased libido, impotence, decreased sperm count and gynecomastia may be noted.
Thyroid function tests
• Serum TSH is low
• T3, T4, and free thyroxin are raised (T3 is more sensitive for hyperthyroidism because there are occasional cases of isolated T3 toxicosis).
• TSH receptor antibody levels are usually high in Graves’ disease.
• Antithyroglobulin or anti microsomal antibodies are usually elevated in Graves’ disease.
• Serum ANA and anti- DNA are also elevated without evidence of SLE.
Thyroid radioactive iodine scan
It is performed in a diagnosed cases of thyrotoxicosis.
High radioactive iodine uptake occurs in Graves disease and toxic nodular goiter while uptake is low in subacute thyroiditis.
MRI
MR! of orbits is the imaging method of choice to visualize Graves’s ophthalmopathy.
• Hypercalcemia
• Increased alkaline phosphatase
• Anemia decreased granulocytes.
• Raised ESR in subacute thyroiditis.
Following are the three methods of treatment of hyperthyroidism
1 . Antithyroid drugs
2. Subtotal thyroidectomy
3. Radioactive iodine
Strategy
Anti-thyroid drugs are first tried for patients less than 40 years, if there is relapse then consider surgery.
Radioactive iodine may be given in patients more than 40 years and those who develop recurrence after surgery.
• Carbimazole ( Neo- Mercazole 5mg)
• Propylthiouracil
Mode of action
These drugs reduce the synthesis of new thyroid hormone by inhibiting the iodination of tyrosine.
Indications
The first episode of hyperthyroidism in patients of less than 40 years of age, or patients with mild thyrotoxicosis, or fear of radioactive iodine.
Agranulocytosis (manifests as severe sore throat due to infection or unexplained fever).
Nausea, vomiting
Rash.
Propranolol
Most manifestations of hyperthyroidism are mediated via the sympathetic system; therefore beta-blockers provide rapid symptomatic control.
Beta-blockers also decrease the peripheral conversion of T4 to T3.
Indications
1. Recurrent hyperthyroidism after a course of antithyroid drugs in patients of less than 40
years.
2. Initial treatment in males with large goiters and in those with severe hyperthyroidism.
3 m Poor drug compliance
1 . Patient must be euthyroid before the operation
1 . Postoperative bleeding, laryngeal nerve palsy
2. Hypothyroidism within one year
3 . Recurrent hyperthyroidism
There are characteristic eye features in Grave’s disease.
Proptosis & limitation of eye movements is direct effects of the inflammation, while conjunctival oedema, lid lag, and corneal scarring are secondary to the proptosis and lack of eye cover.
• Difficulty in reading / distant vision
• Double vision
• Grittiness
• Protrusion
• Decreased acuity
• Limitation of eye movements
• Conjunctivitis/chemosis
• Lid lag / lid retraction
• Exophthalmos