Homeopathy is a system of alternative medicine developed in the late 1700s by Samuel Hahnemann. It is based on the principle of "like cures," which suggests that a substance that causes the symptoms of a disease in healthy people can also be used to treat those same symptoms in sick people. Homeopathy uses diluted preparations of natural substances, such as plants and minerals, to stimulate the body's self-healing processes. It is used to treat a wide range of physical, mental, and emotional imbalances, from minor ailments such as colds and headaches to more acute conditions such as asthma and depression. Homeopathy is considered by many to be a safe and effective form of treatment.