8-15 mmHg is the lightest compression level, intended for general leg comfort, mild end-of-day fatigue and everyday support rather than the management of diagnosed venous disease. It suits long days on your feet, desk-bound work and travel, and it is the easiest level to put on and get used to if you have not worn compression before. No prescription is needed at this level. If you have persistent swelling, visible varicose veins or skin changes, 15-20 mmHg or above is likely more appropriate and worth discussing with a clinician.