Skin is probably the largest of the elimination channels. Through the skin, toxins are eliminated which brought to the surface of the skin from the blood. When the regular elimination channels sluggish or partial plugged up such as your colon being constipated, not all the toxins out through your feces.
Toxins that accumulate in the colon tend to move into the blood, when colon walls have been weaken through constant constipation or abused through eating excessive junk food. Once in the blood they move to the liver for detoxification.
If you are frequently constipated, than your liver will be working too hard and not able to detoxify all the toxins of the colon. Hearts will save a lot of these toxins on its own and other networks where in, the joints of your body tissues, organs, cells and skin.
If you have excessive toxins and the immune system unable to detoxify them, these toxins will moved to the surface of the skin through the blood where they enter the hair pores - follicles - and try to move to the skin surface. When your pores are not working properly, excessive toxins in the pores can cause acne.
If your body skin clean and pores open and unclogged, toxins will move out through the pores without creating pimples or eruptions. The skin normally moves 1-2 pounds of toxins out of your skin everyday.
You can tell when your pores open. You sweat freely during exercise. If you do not sweat much during hot weather or during exercise, then your skin pores are probably plugged.
To keep your skin active and serving as a good channel of elimination you need to brush your skin every day before you shower or during your shower. When you brush your skin, brush in one direction, from the legs to your heart.