Diagnosis

Hypothyroidism Replacement Therapy

Signs and Symptoms1-3

  • Weight gain and oedema/myxedema
  • Hair loss
  • Dry skin
  • Cold intolerance
  • Constipation
  • Dyslipidaemia (hypercholesterolaemia)
  • Lethargy
  • Depression
  • Irregular menstruation
  • Infertility
  • Goitre
  • Myalgia
  • Anaemia
  • Decreased cognitive function
  • Cramps
  • Asthenia
  • Hoarseness

Expected Laboratory Results4

Clinical hypothyroidism

High TSH with free T4 and/or T3 levels below reference values

Subclinical hypothyroidism

High TSH with free T4 and T3 levels within the reference values

Autoimmune hypothyroidism

Positive Anti-TPO and/or ATg

Note: There is often no direct correlation between laboratory findings, i.e. between the degree of alteration in TSH, free T4 and T3 and the intensity of clinical findings.

Recommended Laboratory Results4

Diagnosis

Diagnosis: TSH + free T4

Complex cases

TSH + free T4 + T3

Suspected autoimmune hypothyroidism

TSH + free T4 + ATPO/ATg

Monitoring

TSH and free T4 for adjustment of therapy (4 to 6 weeks after start of treatment, 8 weeks after dose change): annual long-term TSH may be sufficient.

Diagnostic Methods1,4,5

Clinical history and physical examination

Suspected hypothyroidism is usually pinpointed by medical history (see symptoms) and a physical examination (see signs, e.g. goitre).

Laboratory tests

Serum levels of thyroid hormone (free T4 and TSH).