Not enough information.
How long has this been happening?
Any serious illnesses or injury or operations in the past?
Any pain or colouration of the skin?
It has been happening on and off for about 18 months. No pain at all. Some times it is a bit reddish, but not all the time. i have started walking about the house in bare feet, but it still swells up.
Thanks micmac.........well nothing "life threatening" come to mind and the likeliest reason is that your veins on the left side of the leg are not draining properly. You could see your GP who may instigate X-Rays on your veins, but if I were you and if the swelling was the only problem, then I might "live with it"
However, the decision is yours.