Table 2. Clinical features of glucocorticoid withdrawal syndrome, adrenal insufficiency and underlying disease flare.

	Glucocorticoid withdrawal syndrome	Adrenal insufficiency	Underlying disease flare
Symptoms	Fatigue, malaise, sleep disturbance, arthralgia	Fatigue, malaise, nausea, arthralgia	Fatigue, malaise, disease-specific symptoms
Signs	May be signs of glucocorticoid excess	Postural hypotension, weight loss	Disease-specific signs
Laboratory	Normal electrolytes	Hyponatraemia, hypoglycaemia	Rise in inflammatory markers, disease-specific indicators of flare of underlying disease
Glucocorticoid dose and timing of symptom onset	Any point during the taper, often at a prednisolone dose below 15 mg/day [NB1]	Prednisolone dose less than 5 mg/day [NB1], or during intercurrent illness	Any point during glucocorticoid taper, especially if rapid dose reduction
HPA axis testing	Rarely indicated if prednisolone dose is above 5 mg/day	Low morning cortisol and low ACTH	Rarely indicated if prednisolone dose is above 5 mg/day

ACTH = adrenocorticotrophic hormone; HPA = hypothalamic–pituitary–adrenal

NB1: Or equivalent dose of another glucocorticoid (see Table 1 for relative activity of commonly prescribed glucocorticoids).