A variety of conditions from a broken ankle to pregnancy or gout can necessitate elevating of your foot. Doctors typically recommend raising your affected foot above heart level to prevent swelling and pooling blood. Elevating your foot during the day is easy, but doing so while asleep is a bit more challenging. Keeping your foot raised throughout the night isn't difficult, but does require understanding your own sleep patterns to ensure consistent and proper elevation of your foot.
Find a firm and supportive pillow on which to rest your feet. Avoid feather or down pillows, which sink easily, thus lowering your elevated foot. Pillows made of memory foam are also a good choice for a supportive resting place. Use a longer king-size pillow, if possible, as it will keep your foot elevated if you roll over while sleeping. If necessary, safety pin the cases of two pillows together to achieve the proper height.
Place the pillow under your knees, which will cause your foot to rise. Your knee is a natural bending point in your lower leg, and a good place for elevated support. Avoid placing the pillow under your foot only without supporting the rest of your lower leg, because this set-up places unnecessary strain on your unsupported knee.
Make four loops of packing tape and place them on the bottom corners of the pillow. Press the adhesive-backed pillow into your mattress before moving your knee on top. If you are a restless sleeper, the adhesive backing will prevent the pillow from sliding out of position while you sleep.
Even if only one foot requires elevation, some people find raising both feet is an easier and more comfortable position to hold while sleeping.