The kidney, more specifically the glomerulus, is often injured during systemic diseases. These secondary glomerulonephritides often manifest with proteinruia, heamturia, and impaired kidney function occasionally. Diagnosis is challenging, and treatments frequently incorporate immunomodulatory drugs with potential for severe side-effects. The 2018 Secondary Glomerular Diseases issue of NephSAP presents the reader with the latest updates on diagnosis, treatment, and outcomes of a wide range of glomerular diseases likely encountered in practice. Recommendations are offered based on the best available evidence. All relevant, randomized, controlled clinical trials are discussed. The reader will also be introduced to reasearch-based findings of special clinical relevance such as biomarkers of disease activity and response. Gaps in knowledge are indicated, and considered in the context of future investigation. After studying this issue of NephSAP, readers are invited to test their knowledge in a series of challanging case studies and questions, accompanied by detailed explanations of the best answers.