At the time of breast cancer diagnosis, L-Dex values are similar to normative values. Identified maximum changes in L-Dex values 12 months postoperatively suggest that frequent L-Dex measurements during that time frame are of potential clinical benefit. Our findings are consistent with research supporting an L-Dex value of >7 as indicative of clinical lymphedema with subclinical lymphedema logically occurring at somewhat lower likely, near >6.5. Open access: No View