They affect some chemical processes within and between cells. Chemists use sensitive magnetic equipment to measure simple and complex molecules. Researchers at Harvard found that salt water passes a membrane quicker with a magetic field. They can affect nerve signals. High strength magnets can cause anesthesia, through a principle in physics called the Hall effect.
Magnets can stop epileptic seizures.
They are also used to study and map nerve structures deep in the brain, normally only accessible during brain surgery. I hope the above has helped to inform you about the exciting new field of biomagnetics which has great potential to help people. We are clearly seeing a new day in medical sciences and health care with the expanded awareness and use of complementary techniques of care. Several books have been written on magnetic therapy. Check your library or bookstore.