Bloods
FBC (anaemia), CRP, (infection), U+E (CKD), LFTs (CLD),
Fe studies, B12/folate (anaemia), bone profile (Ca, phos, ALP), TFTs (hypothyroid)
Coeliac screen (Coeliac disease)
Hormone profile (LH, FSH, oestrogen, testosterone, GH)
Dex suppression test (Cushings)
Karyotyping (chromosomal disorder)