Magnet is any material that has a magnetic field. It can be in the form of a permanent (static) magnet or an electromagnet. Permanent magnets do not rely upon outside influences to generate their field. Electromagnets rely upon electric current to generate a magnetic field.
All magnets possess a property called polarity. A magnet's power of attraction is strongest at its opposite ends, usually called the north and south poles. The north and south poles attract each other, but north repels north and south repels south.
Magnets come in different strengths, most often measured in units called gauss (G). For comparison purposes, the Earth has a magnetic field of about 0.5 G; refrigerator magnets range from 35 to 200 G; magnets for the treatment of pain are usually 300 to 5,000 G; and MRI (magnetic resonance imaging) machines widely used to diagnose medical conditions non-invasively produce up to 200,000 G.
There are several different types of material that magnets are made from. The main two types used in magnetic therapy are Ferrite sometimes called ceramic magnets and neodymium magnets.
Ferrite or ceramic magnets are made of a mixture of iron and barium. They can be made into large shapes and hold their magnetic strength for many years.
Neodymium magnets, is a more recent discovery, and are made of iron, boron and the rare earth neodymium. These magnets are very strong in comparison to their mass and also hold their strength for many years. Neodymium magnets have 10 x the power of Ferrite magnets.
Typically, the magnets are placed directly on the skin that come into close contact with the body.
Because it contains iron, blood will act as a conductor of magnetic energy. Static magnets increases the flow of blood and, therefore, increase the delivery of oxygen and nutrients to tissues.