Hypothyroidism Flashcards
What are the symptoms of Hypothyroidism?
What are the causes of Hypothyroidism?
Common –Hashimotos (Autoimmune), Iatrogenic (Post-surgical, radioiodine), Iodine Deficiency, Atrophic Thyroiditis (Autoimmune)
Others – Hypothalamic/ Pituitary lesion, Invasion (Amyloidosis, Sarcoidosis, Hemochromatosis), Drugs (Amiodarone, Lithium), Chronic iodine excess can cause hypothyroidism
What are the symptoms of Hypothyroidism?
Symptoms:
Systemic – Tiredness, Lethargy, Cold Intolerance, Weight Gain, Dry Skin, Hair Loss, Cramps, Weakness
Gastro – Constipation, Decreased appetite
Repro – Menorrhagia, Reduced libido.
Cardio – Bradycardia, Pericardial effusion, Ischaemic Heart Disease
Others – Depression, Poor Memory, Puffy Face, Hoarse Voice, Carpal Tunnel,
Fluid Retention (Low temperature increases fluid retention) – Non-pitting oedema, Ascites, Pericardial effusion, Pleural Effusion, Impaired hearing (fluid build-up in middle ear)
Risk Factors:
Personal or family history of any other autoimmune conditions (Pernicious anaemia, Addison’s, Type 1 diabetes) – Predisposes to increased likelihood of autoimmune hypothyroidism (Hashimotos or Atrophic Thyroiditis)
Previous Thyroid problems and treatment – Commonly secondary to thyroid removal or radioiodine treatment
Specific Question to ask:
Symptoms of any other hormone imbalances (e.g. skin depigmentation, atrophic breasts, galactorrhoea, Cushing’s syndrome, or acromegaly) indicate a central pituitary/hypothalamic problem
Headaches, vision problem indicate a central pituitary problem
Differentials:
Anaemia - Differentiated by bloods, showing a change in TSH
Depression - Will not respond to levothyroxine and TSH/T4 levels will be unchanged
What are the signs of Hypothyroidism?
End of the bed: Drowsy/comatose Obese Hands: Bradycardia Slowly Relaxing Reflexes Cold extremities Carpal Tunnel Neck: Goitre – Hashimotos, Iodine Deficiency Face: Dry/thin hair Puffy Face Husky Voice Abdomen: Ascites – Fluid retention Chest: Pleural effusion – Fluid retention Pericardial effusion – Fluid retention Legs: Reflexes relax Slowly Non-Pitting oedema – Fluid retention
What investigations will you order in suspected Hypothyroidism?
If person has thyroid goitre or nodule use 2-week referral to see a specialist as may be cancerous (Thyroid cancer normally has normal thyroid levels)
Bedside:
ECG – Looking for any bradyarrhythmia’s
Bloods:
Thyroid function tests - T3/4 (Will be low), TSH (Will be raised in primary or low in secondary
FBC – Looking for anaemia (normocytic = anaemia of chronic disease) (macrocytic = pernicious anaemia) (Microcytic = Iron deficiency due to menorrhagia)
Thyroid Autoantibodies – Peroxidase and Thyroglobulin (Hashimotos) or Blocking TSH (Atrophic)
Lipids – Hypothyroidism can cause hypercholesterolaemia
Blood Glucose - associated with Type 1 diabetes
Cortisol – They are at a higher risk of Addison’s disease as it is another autoimmune condition
Imaging:
US Goitre – If person has thyroid goitre or nodule use 2-week referral to see a specialist as may be cancerous (Thyroid cancer normally has normal thyroid levels)
What is the treatment of Hypothyroidism?
Lifestyle:
Give iodine replacement if low
Medical:
Lifelong Levothyroxine – Start with a low dose and titrate up against TSH levels and symptoms
Myxoedemic coma:
IV levothyroxine
IV hydrocortisone (Many patients will have Addison’s disease)
Supportive therapy – Correct electrolyte disturbances, warm patient with blankets
What is Hypothyroidism
Hypothyroidism is the clinical syndrome brought about by low levels of Thyroid hormones T3/T4, Thyroid hormones usually increase basal metabolic rate
Patients with Hypothyroidism are at risk of myxoedemic coma, this is a rare complication of hypothyroidism that has a very high mortality rate. Patients present comatose, hypothermic and with signs of hypothyroidism (normally after a precipitating factor like infection or having not taken their medication)
