How serious is membranous nephropathy?

Depends: Depends on severity, response to treatment, also underlying contributors such as lupus, hepatitis b or c, cancer or meds such as Penicillamine (not penicillin) or nsaids.Not all cases have an obvious contributor.Mild cases frequently go into remission without treatment.Severe or refractory cases may lead to dialysis or kidney transplant.A nephrologist can give a more specific answer case-by-case.

Depends: This disease is one that depends on two factors: the level of GFR (level at which your kidney is working) and the amount of protein you spill in your urine. The lower the level of you GFR and more protein spill in your urien could mean serious problems. If the converse is true, then not so serious. In any respect, you need to see a kidney doctor to help manage this disease.