The work performed was observational, cross-sectional, analytical, inferential and unicentric. In order to prove its feasibility, the researcher conducted a preliminary investigation work (pilot study) with a total of 40 patients (aged 40 to 85) who were treated at the Service of Angiology and Vascular Surgery of the Hospital de Sant Pau (Barcelona, Spain). These patients were selected to verify their data and then the researcher performed a statistical study from a descriptive and inferential point of view to find out whether there is a relation betwen the prevalence of onychodystrophy and the degree of severity of chronic venous disease. In order to minimise methodological mistakes in the outcomes and sampling, the study has been carefully defined and framed.