DR Medhat MRCP

Subclinical Hypothyroidism
Basics
- Normal T3 – T4
- High TSH
- No obvious symptoms
Significance
- Risk of progressing to overt hypothyroidism is 2-5% per year (higher in men)
- Risk ↑ by presence of thyroid autoantibodies
Treat if
1) TSH > 10
2) Thyroid autoantibodies positive
3) Other autoimmune disorder
4) Previous treatment of graves' disease
Sick Euthyroid Syndrome: (now referred to as non-thyroidal illness)
- It is often said that everything (TSH, thyroxine and T3) is low.
- In some cases the TSH level may be normal.
- Changes are reversible upon recovery from the systemic illness.
- Usually in hospitalized patients.
Investigations of the case of hypothyroidism & other thyroid disorders :
Abnormality TSH Free T4 Interpretation
Thyrotoxicosis (e.g Grave`s
disease)
↓ ↑ In T3 thyrotoxicosis, T4 will
be normal
1ry (atrophic) hypothyroidism ↑ ↓
2ndry hypothyroidism ↓ ↓ Steroid therapy is required
prior to thyroxine
Sick euthyroid syndrome ↓( May be N) ↓ Common in hospital patient
Poor compliance with thyroxine ↑ /↑
Steroid therapy
↓
Management of hypothyroidism :
1) Levothyroxine (Eltroxine) follow up with TSH (ideally keep between 0.5-2.5)
2) Treatment of myxoedema coma.
3) Treatment of subclinical hypothyroidism.