Investigation of thyroid nodules begins clinically and is definitely followed by a laboratory evaluation of thyroid status. Imaging provides valuable info, but expert cytology from great needle aspiration biopsy may be the important investigation to define which thyroid nodules require surgical removal. The combination of fine needle aspiration biopsy with ultrasound yields better sensitivity and specificity than biopsy guided by palpation alone. Not absolutely all nodules require biopsy.The dual toxicities and focus on cells were originally revealed whenever a band of healthy Belgian females developed renal failure and UUC after ingesting Aristolochia natural herbs to lose excess weight. Other situations of aristolochic acid nephropathy and UUC were subsequently reported worldwide. Lately, Dr. Grollman and co-workers proved AA to be the causative agent of endemic nephropathy in the Balkans, solving a 50-year-older medical mystery that pointed to the ingestion of Aristolochia clematitis, or birthwort, within wheat. The analysis results were reported in Kidney International recently.