Ultrasound is a widely used tool for diagnosing tissue and fluids. In lymphological questions, edemas of the lower extremity can be classified differentially based on the clinical findings and the anamnesis. The examination, however, is highly dependent on the technique and the examiner’s experience. Ultrasound can confirm the diagnosis of lymphedema if the thickness of the cutis is measured correctly—that is, with a lead-in gel plate. In lymphedema, the cutis is thicker than in healthy individuals. Echoless gaps may be detectable. Since cutis thickness measurement and sonoelastography findings are easy to collect, they have proven helpful in diagnosing doubtful cases and monitoring progress.