Our blood will no longer be recognizable in the future. It will be filled with man-made products, designed to indefinitely extend our lives. There will be synthetic blood, which will heal wounds faster than real blood. There will be genetically engineered bio-organisms designed to battle specific diseases and infections, injected into us in the way that vaccines are now. There will be nanobots, built to do things like scrape plaque off the side of arteries. People will even have messages encoded on specially designed DNA, used for things like identifying a body and for keeping a permanent copy of your will embedded in the proteins of the DNA. We will be a river of technology, passing through us constantly, unnoticed but always affecting us.