Endocrine System >
Hypothyroidism
“The clinical effect of lack of thyroid hormones”
Aetiology & Pathogenesis
- Primary Autoimmune Hypothyroidism:
- Primary Atrophic Hypothyroidism
- No goitre
- Diffuse lymphocytic infiltration of the thyroid, leading to atrophy
- Hashimoto’s Thyroiditis
- Goitre due to lymphocytic + plasma cell infiltration
- May be hypothyroid or euthyroid
- Primary Atrophic Hypothyroidism
- Other Primary Hypothyroidism:
- Iodine Deficiency
- Post-Thyroidectomy / Radioiodine treatment
- Drug-induced i.e. Antithyroids, Amiodarone, Lithium, Iodine
- Subacute Thyroiditis
- Temporary hypothyroidism after hyperthyroid phase
- Secondary Hypothydoisim:
- Not enough TSH due to Hypopituitarism
- Very rare
Clinical Presentation
- Symptoms:
- Tiredness, Sleepy, Lethargic
- Low Mood
- Cold Intolerance
- Weight Gain
- Constipation
- Menorrhagia
- Hoarse Voice
- Decreased Memory/Cognition
- Dementia
- Myalgia
- Cramps
- Signs (BRADYCARDIC):
- Bradycardia
- Reflexes slow
- Ataxia (cerebellar)
- Dry thin hair/skin
- Yawning/drowsy/coma
- Cold hands
- Ascites
- Round puffy face/obese
- Defeated demeanour
- Immobile +/- ileus
- CCF
Investigations
- Bloods:
- High TSH
- Low T4
- High Cholesterol + Triglycerides
- Macrocytosis
- Imaging: n/a
- Special: n/a
Management
- Levothyroxine
Complications
- Myxoedema Coma
- Pregnancy
- Eclampsia
- Anaemia
- Prematurity
- Low birth weight
- Stillbirth