When people do a detoxification or internal cleansing program, very often they will get an increase of disease symptoms or uncomfortable physical reactions (known as a Herxheimer reaction) such as fatigue or exhaustion, irritability, cold or flu symptoms, headaches, skin outbreaks, nightmares, and more. Very often this can discourage or frighten the person new to cleansing who thinks something is wrong and stops the cleanse. Doctors often dismiss the concept of a cleanse reaction as fantasy not based in science. In fact, science has documented what happens in Herxheimer reactions, by Nobel laureates and scientists at very respected universities. So what causes cleanse reactions? Very simply, your body has two circulatory systems, the blood system, and the lymph system. The blood system's job is to circulate nutrients to all the cells in the body. The lymph system is designed to remove waste products and toxins. The lymph vessels parallel all of the blood vessels in the body, with the body's cells sandwiched in between. But unlike the blood system's heart, there is no pump to circulate lymph. When you take supplements such as herbs, for example, to detoxify the body, the supplements loosen or release toxins and waste products from tissue quickly and in greater quantity than usual. These toxins eventually make it into the lymph vessels and circulate by muscle contraction, deep breathing, movement, and exercise from the tiny capillaries in the extremities back toward larger lymph vessels in the thorax, or body's center. The lymph vessels have one-way valves throughout that only allow lymph to flow toward the thorax. Along the way, cells in the lymph vessels and nodes called lymphocytes clean the lymph by digesting and transforming toxins to nontoxic compounds. During a cleanse, the cells dump toxins faster than the lymph system can remove them, and so they are dumped back into the blood system and recirculate through the body, giving you cleanse reactions.
By the way, with cancer, the lymph nodes that produce lymphocytes are often overwhelmed with toxins and acid and become cancerous themselves. Standard medical procedure is to remove the lymph nodes. Natural therapies seek to get the lymph flowing and toxins flushed out of the body. Rebounding, jumping on a mini trampoline, and exercise are two ways to get the lymph flowing toward the thorax for elimination. Cancer patients often lack energy and rebounding is easier than other forms of exercise, which is why you see it promoted for health.
Dr. Stephen E. West, son of Nobel nominee Dr. C. Samuel West, has some great videos on lymphology and more at YouTube:
— Ken Rohla