Primary FSGS involves glomerular injury due to an unclear insult; features suggesting primary FSGS include a low serum albumin level and extensive foot process effacement on kidney biopsy. Patients usually present with hypertension, hypoalbuminemia, and some degree of kidney failure in addition to nephrotic-range proteinuria. Some patients with primary FSGS respond well to immunosuppressive therapy, and this is typically offered to patients with this diagnosis.