In the realm of pseudoscience, there is a belief that magnets are magic. Many people do not understand how magnets work and often fall prey to charlatans that preach about the healing effects of magnetic fields.
Let's look at how these magic magnets are supposed to work: Your blood contains iron. Iron is a ferrous material that will align with any magnetic field it passes through. Charlatans attempt to use this to suggest that blood flow is improved by wearing a “helpful” magnetic field. How exactly the molecular rotation of atoms in individual blood cells would help is a mystery.
Some suggest that the magnetic field will pull out "toxins" from your blood to improve your health. They never explain these toxins, why they're magnetic, and where they go once out of your blood. Others believe that the magnets will act as a type of Star Trek-esque deflector shield to ward away supposedly harmful radiation that they believe to be emitted from household products. Ever seen people wearing tin-foil hats? Yeah, those people. There is no proof that any of these things are possible.
Believe it or not, some creatures DO use electromagnetism. Many types of birds can sense magnetic fields and use that to navigate. Electric eels can generate an electrical field for hunting and defense.
Humans have developed ways to use electromagnetic fields in the medical industry. Electromagnetic fields can heat biological tissue. Magnetic Resonance Imagery is used to provide images of various parts of the body. I recently had an MRI that showed tears in several ligaments in my ankle. We have also developed specific medical therapies that rely on powerful, pulsed magnetic fields to depolarize neurons in the body's nervous system momentarily. This has been shown to have some therapeutic value in relieving pain. Similar processes have been found to stimulate bone regrowth.
Remember that these medical procedures use extremely powerful electromagnets that are many orders of magnitude stronger than anything you could safely wear on your wrist. The only way to come close to this power is by wearing a neodymium magnet. This is somewhat dangerous as the power of attraction is sufficient to pierce the skin or break a bone. You haven't felt pain until you've pinched yourself between two strong neodymium magnets, and the only way to get them apart is a painful side slide that will cut the edge of your skin.
In any case, that magnetic field would have a very short range and is entirely static. The oscillating magnetic fields mentioned previously change polarities hundreds of thousands of times per second. Magnet bracelets have a magnetic field strength measured in milliTesla, while these medical magnetic field devices are several Tesla strong. These two devices are miles apart in terms of capability.
Hopefully, this article has shined some light on another "alternative medicine" practice that you can now protect yourself from. Remember, some might ask â€œWhat's the harm in using something like this? Consider this: some people rely on pseudo-science believing snake-oil salesmen instead of their regular doctor. Marketing false medicine can prevent someone from getting the help they need, and there's a lot of harm.