I know you are suffering from Henoch-Schӧnlein purpura, and then this disease spread to Kidney Disease. You told me that you have edema, shortness of breath before taking diuretic medicines.
And the reason why patients have swelling/edema is that the kidneys get damaged,especially the renal tubules get damaged. The main function of Renal tubules is re-absorption the useful things from initial urine, and get rid of the waste things into the urine. If the renal tubules get damaged, the water/liquid can’t get rid of from the urine, so they begin to go into human body. some patients begin to present swelling in eyelid, then leg, foot etc.
However, because of the renal tubules get damaged, so the useful product like protein can't re-absorption into human body, and the waste product like liquid can't discharge into urine, more and more liquid go into the human body,like eyelid,chest,heart,liver. So patients present difficult in breath,hydrothorax,Pleural effusion,Pericardial effusion etc.
