HypothyroidismGroup A

UNIT 5: ENDOCRINE

Hypothyroidism Background: Primary hypothyroidism - Most common cause is HASIMOTO’S

THYROIDITIS diagnosed in >80% of cases – is an autoimmune disease

Secondary hypothyroidism - <5% cases due to deficient pituitary production of TSH

Prevalence 3x higher in women compared to men Annual incidence rate 1-2 per 1,000 women Presentation of symptoms in elderly may be atypical or absent Prevalence increases with age Caucasians higher incidence than non-Caucasians

Risks:

Risks highest in persons with: Type 1 diabetes mellitus Family history of thyroid disease History of head/neck cancers treated with radiation therapy Previous radioactive iodine treatment Previous thyroid surgery

Case:

Mr. T. presents to you concerned about her weight gain and fatigue. Both of these problems have been problems for years. Recently, a friend told her these problems may be because her thyroid is not working properly and she wants to have her thyroid checked.

What other signs and symptoms would you ask Ms. T. about?

What other signs and symptoms would you ask Ms. T. about? Clinical Signs and Symptoms

Fatigue (reported by this patient) Cold intolerance Constipation Impaired memory Slowed mentation Depression Ataxia Muscle weakness Muscle cramps

Clinical Signs & Symptoms Continued

Menstrual disturbance Hoarseness Goiter Periorbital edema Weight gain (was reported by this patient)

Ask about family history:

Personal or family history of associated autoimmune disorders:

Pernicious anemia Adrenal insufficiency Diabetes mellitus Type 1 Ovarian failure Celiac disease Sjogren’s syndrome Multiple sclerosis

Ask about previous thyroid injury or treatment

Thyroidectomy or other neck surgery Radioactive iodine therapy External radiation therapy

Ask about current medications

Drugs that impair thyroid function: Lithium Amiodarone Aminoglutethmide Interferon a Thalidomide Betaroxine Stavudine

Ask about pituitary disorders

Pituitary tumor Signs of sellar mass: headache, bi-temporal

hemianopsia or diplopia History of pituitary surgery or radiotherapy History of head trauma

References:

Roberts, C. G., & Ladenson, P. W. (2004). Hypothyroidism. Lancet, 363, 793-803.

Clinical practice guideline: Investigation and Management of Primary Thyroid Dysfunction. (2008). Retrieved February 1, 2009 from http://topalbertadoctors.org