Nephrotic syndrome (NS) consists of peripheral edema, heavy proteinuria, and hypoalbuminemia, often with hyperlipidemia. Patients typically present with edema and fatigue, without evidence of heart failure or severe liver disease. The diagnosis of NS is based on typical clinical features with confirmation of heavy proteinuria and hypoalbuminemia. The patient history and selected diagnostic studies rule out important secondary causes, including diabetes mellitus, systemic lupus erythematosus, and medication adverse effects. Most cases of NS are considered idiopathic or primary; membranous nephropathy and focal segmental glomerulosclerosis are the most common histologic subtypes of primary NS in adults. Important complications of NS include venous thrombosis and hyperlipidemia; other potential complications include infection and acute kidney injury. Spontaneous acute kidney injury from NS is rare but can occur as a result of the underlying medical problem. Despite a lack of evidence-based guidelines, treatment consisting of sodium restriction, fluid restriction, loop diuretics, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy, and careful assessment for possible disease complications is appropriate for most patients. Renal biopsy is often recommended, although it may be most useful in patients with suspected underlying systemic lupus erythematosus or other renal disorders, in whom biopsy can guide management and prognosis. Immunosuppressive treatment, including corticosteroids, is often used for NS, although evidence is lacking. Routine prophylactic treatment to prevent infection or thrombosis is not recommended. A nephrologist should be consulted about use of anticoagulation and immunosuppressants, need for renal biopsy, and for other areas of uncertainty.