If you're talking about general inflammation... Medical guidance is best but in general what helps me is: •Raise your leg above the level of your heart, easier lying down 😃 •Cool helps too, that will depend on Medical guidance though so ask a doctor or physiology about your condition, I use ice packs from the freezer, and leave my legs out from under the duvet •Ibuprofen (it's called different things in different places) •Compression stockings for when you are moving I hope things improve. If it's a lump you need to find out the cause.
Is the imflammation caused by an injury or has it just started for no reason? I would suggest seeing you're doctor if the imflammation has just shown up for no reason especially if it's painful as well.
As Fon said you should lay down and put your leg up on a few pillows or cushions so it's raised above your heart. Use heat and cold compresses alternating....cold first then leave 20 minutes before putting heat on it. Use an anti imflammatry like ibuprofen to help bring down any swelling. If any of this doesn't help then you really need to see your Doctor.