Clinical decision support systems (CDSS) provide health professionals with patient-specific advice and recommendations to help with clinical decision-making. CDSS can generate alerts, aid with diagnosis, and assist with treatment planning. They utilize medical knowledge combined with individual patient data to produce customized assessments or advice. Early systems included MYCIN and INTERNIST-I, while successful current CDS systems are DXplain and QMR. CDSS can benefit healthcare by improving processes and outcomes given limited resources and increasing demand, though they may also change the physician-patient relationship or have legal implications.