Nephritic syndrome is a constellation of hematuria, proteinuria, hypertension, and in some cases acute kidney injury and fluid retention characteristic of acute glomerulonephritis. Infection-related glomerulonephritis, IgA nephropathy, lupus nephritis, membranoproliferative glomerulonephritis, and antineutrophil cytoplasmic antibody–associated vasculitis are the most common diseases in nephritic syndrome that primary care physicians might encounter in practice such that a solid comprehension of these can lead to earlier detection. This article describes the pathophysiology, incidence, clinical presentation, treatment, and disease progression of these nephritic syndrome entities, and provides guidance for when to refer to a nephrologist.