Secondary causes and risk factors assume far greater importance in mal
e osteoporosis than in female osteoporosis. The principal problem in d
ealing with male osteoporosis, above all in young men, is the difficul
ty to find a curable aetiology. Six groups of aetiologies can be drawn
up: toxic causes or causes due to a change in the general state of he
alth, drug-induced causes, renal causes, hormonal causes, exceptional
causes and lastly the idiopathic form. The minimum number of investiga
tions necessary so as to be quite sure not to overlook these various a
etiologies is proposed.