There are numerous risk factors for patients to develop excessive polypharmacy. The most prominent risk factors are associated with sociodemographics and the patients’ conditions. Risk factors associated with patient behavior, such as patient’s self medication with all types of medications, have not been observed to the same extent but might be at the same level of importance for patients developing excessive polypharmacy. Risk factors related to physicians, and the interaction between patient and physician, are studied to a much lesser extent. The few studies conducted regarding the large variation in physicians’ individual prescribing practices, in terms of polypharmacy, add another perspective to the complexity of the area. Interventions aiming to improve communication between GP and hospital specialist, to create support systems for medical reviews that include all patients’ medications, and to improve the knowledge of multiple prescribing might have the largest potential to better manage excessive polypharmacy.