<unk> : Excess circulating hormone resulting from thyroid gland hyperfunction
Thyrotoxicosis: Excess circulating thyroid hormone originating from any cause
Primary<unk> 
Graves disease (toxic diffuse goitre)
Most common cause of<unk>  (85% of cases)
Autoantibodies bind to TSH receptor and stimulate thyroid hormone production and release 
Associated with diffuse goitre, ophthalmopathy, local dermopathy
Strong genetic relationship, often found with other autoimmune disorders 
Toxic multinodular goitre
2nd most common cause
Multiple autonomously functioning nodules 
Milder, more gradual disease than Graves'<unk> 
Toxic nodular (adenoma) goitre
Single hyperfunctioning nodule
Similar presentation to multinodular goitre, but less common 
Most common cause of<unk>  (85% of cases)
Autoantibodies bind to TSH receptor and stimulate thyroid hormone production and release 
Associated with diffuse goitre, ophthalmopathy, local dermopathy
Strong genetic relationship, often found with other autoimmune disorders 
2nd most common cause
Multiple autonomously functioning nodules 
Milder, more gradual disease than Graves'<unk> 
Single hyperfunctioning nodule
Similar presentation to multinodular goitre, but less common 
Secondary<unk> 
Thyrotropin-secreting pituitary adenoma
Thyroiditis
Hashimoto thyroiditis
Autoimmune disorder
Thyroid antibodies and lymphocytic infiltration 
Painless goitre
Initially gland is overactive<unk>  state) followed by hypothyroidism
Subacute painful thyroiditis (de Quervain thyroiditis)
May be caused by viral infection
Viral prodrome followed by anterior neck pain
Tender thyroid (palpation, head movement, swallowing)
50% have symptoms of hyperthyroid lasting 3 - 6 weeks
1/3 have hypothyroidism for up to 6 months
Subacute painless thyroiditis 
Small, non-tender goitre
Mild symptoms
Autoimmune
Postpartum thyroiditis 
3 phases:
Thyrotoxic phase 2 -6 months postpartum (20-30% have only this phase)
Hypothyroid phase lasting 2 -3 months (but may be permanent) (40% have this phase only)
Euthyroid phase within first postpartum year
Some women develop permanent hypothyroidism
70% recurrence in subsequent pregnancies
Suppurative thyroiditis 
Rare
Life-threatening
Infection usually bacterial, but can be parasitic, mycobacterial, or fungal
Usually have pre-existing thyroid disorder and immune compromise
Radiation thyroiditis
Hashimoto thyroiditis
Autoimmune disorder
Thyroid antibodies and lymphocytic infiltration 
Painless goitre
Initially gland is overactive<unk>  state) followed by hypothyroidism
Subacute painful thyroiditis (de Quervain thyroiditis)
May be caused by viral infection
Viral prodrome followed by anterior neck pain
Tender thyroid (palpation, head movement, swallowing)
50% have symptoms of hyperthyroid lasting 3 - 6 weeks
1/3 have hypothyroidism for up to 6 months
Subacute painless thyroiditis 
Small, non-tender goitre
Mild symptoms
Autoimmune
Postpartum thyroiditis 
3 phases:
Thyrotoxic phase 2 -6 months postpartum (20-30% have only this phase)
Hypothyroid phase lasting 2 -3 months (but may be permanent) (40% have this phase only)
Euthyroid phase within first postpartum year
Some women develop permanent hypothyroidism
70% recurrence in subsequent pregnancies
Suppurative thyroiditis 
Rare
Life-threatening
Infection usually bacterial, but can be parasitic, mycobacterial, or fungal
Usually have pre-existing thyroid disorder and immune compromise
Radiation thyroiditis
Autoimmune disorder
Thyroid antibodies and lymphocytic infiltration 
Painless goitre
Initially gland is overactive<unk>  state) followed by hypothyroidism
May be caused by viral infection
Viral prodrome followed by anterior neck pain
Tender thyroid (palpation, head movement, swallowing)
50% have symptoms of hyperthyroid lasting 3 - 6 weeks
1/3 have hypothyroidism for up to 6 months
Small, non-tender goitre
Mild symptoms
Autoimmune
3 phases:
Thyrotoxic phase 2 -6 months postpartum (20-30% have only this phase)
Hypothyroid phase lasting 2 -3 months (but may be permanent) (40% have this phase only)
Euthyroid phase within first postpartum year
Some women develop permanent hypothyroidism
70% recurrence in subsequent pregnancies
Thyrotoxic phase 2 -6 months postpartum (20-30% have only this phase)
Hypothyroid phase lasting 2 -3 months (but may be permanent) (40% have this phase only)
Euthyroid phase within first postpartum year
Rare
Life-threatening
Infection usually bacterial, but can be parasitic, mycobacterial, or fungal
Usually have pre-existing thyroid disorder and immune compromise
Other causes:
Apathetic thyrotoxicosis (elderly, masking comorbidities)
Metastatic thyroid cancer
Iodine-induced thyrotoxicosis
Amiodarone-induced thyroiditis 
Possible mechanisms:
Drug-induced destructive thyroiditis<unk>  caused by iodine load (amiodarone contains a large amount of iodine)
Drug-induced thyroiditis may also occur with interleukin-2, Interferon-α, lithium, tyrosine kinase inhibitors, HAART
Molar pregnancy
Possible mechanisms:
Drug-induced destructive thyroiditis<unk>  caused by iodine load (amiodarone contains a large amount of iodine)
Drug-induced thyroiditis may also occur with interleukin-2, Interferon-α, lithium, tyrosine kinase inhibitors, HAART
Drug-induced destructive thyroiditis<unk>  caused by iodine load (amiodarone contains a large amount of iodine)
Myxedema coma << hypothyroidism < euthyroid ><unk>  >> thyroid storm
Hyperthyroidism
Anemia
Hypothyroidism
Dehydration
Hyperparathyroidism
Fever
Metabolic syndrome
Infection, Sepsis