Bloods
FBC (anaemia), U+Es (deranged electrolytes, high Cr, high urea), GFR (declining), vit D (low), Ca (low), phos (high) PTH (high),
LFTs (high ALP due to bone disorder), glucose (DM),
ESR/CRP (inflammatory cause), immunology (ANA, ANCA)
Virology (HIV, HBV, HCV)