In response to the above.
Swollen foot when pressed stays indented indicates edema or fluid retention in the foot. This often occurs after driving long distance, not moving the legs or the feet for long hours sitting and working on the computer, driving long hours over long distances without stopping or resting, taking a long flight in the now extremely cramped economy class seat without moving about during flight, sometimes swelling of the knees down to the lower legs, the ankles, the entire foot, etc.
Now, when one presses the swollen foot, the skin stays indented, and the indentation shows a dark color, that means there is not only edema but also an accumulation of non-circulating blood in the blood vessels and capillaries that appear blue, which means the blood is dying for lack of oxygen in the blood.
Place the foot under the hot shower or soak the foot in hot water for at least 40 minutes until the skin of the foot turns rosy.
Soaking a foot or leg in hot water actually opens the pores of the skin, and this alleviates edema.
Hot water will also stimulate circulation and this warmed up circulation will carry away the cumulated dying blood from the extremities.
To me, the economy class airline seats are detrimental to both one’s physical and mental health. The bucket driver side seats in dinky cars and the “Porsche Kevlar seats” according to an input I received not long ago will hurt the back. Porsche drivers, which I was one myself, and older model Toyota Sutra drivers all know this well.