Addison's disease is a rare condition which in most cases is caused by autoimmune destruction of the adrenals, leading to deficiency of cortisol, aldosterone and adrenal androgens. Unrecognized the disease is life threatening, but with proper treatment patients can live near normal lives.

The conventional glucocorticoid replacement therapy renders the cortisol levels unphysiological, which may cause symptoms and long-term complications. Glucocorticoid replacement therapy is technically feasible by continuous subcutaneous hydrocortisone infusion (CSHI), and can mimic the normal diurnal cortisol rhythm. This study aims to further evaluate CSHI treatment in terms of metabolic effects, effects on health-related quality-of-life and sleep in an 8 months randomised open label clinical trial with crossover design.

Inclusion Criteria:

• Patients with verified Addison's disease on stable treatment.

Exclusion Criteria:

• Insulin treated Diabetes Mellitus, cardiovascular disease,malignant disease, pregnancy.
• Treatment with glucocorticoids or drugs that interfere with cortisol metabolism (antiepileptics, rifampicin, St. John's wart).