Aims: To clarify the risk factors for frailty to help doctors prevent diseases that cause weakness, through early interventions. Methods: We searched the PubMed, EMBASE, and Cochrane Library databases to identify all relevant studies using the items “frailty,” “weak,” “risk factors,” and “predictive factors” and compared their results. The aging population (≥65 years old) was divided into 2 groups, a “frailty group” and a “robust control group,” and then the characteristics, lifestyles, and comorbidities were compared. Results: We compared the influence of baseline and concomitant diseases on frailty in the elderly respectively, and the analysis of the influence of baseline on frailty found that increasing age, lower weight, female sex, living alone, low levels of exercise, polypharmacy, higher education level, smoking, drinking, malnutrition, and lower vitamin D levels were associated with aging individuals being more likely to experience frailty. The data about concomitant diseases had shown that diabetes, hearing dysfunction, cognitive impairment, poor sleep, a history of falls, pain, and depression can increase the risk of frailty among the elderly population. Conclusion: Characteristics, comorbidities, and lifestyle factors can impact the occurrence of frailty, and relevant influencing factors should be considered.