Phosphoric acid is used in the manufacture of pharmaceutical medications, fertilizers, and detergents. It is also used in sugar refining and to give soft drinks a fruity, acidic flavor. In orthodox medicine, phosphoric acid was once used to stimulate digestion. Now it is used to reduce calcium levels in the blood of people with cancerous or benign tumors in the parathyroid glands (which lie in the neck). This is one of homeopathy's most effective remedies for people who are apathetic and listless. This may be a result of too much studying or stress. Sluggishness and lethargy may also occur after a severe loss of fluids from dysentery or stomach flu. Physical symptoms associated with listlessness and apathy include chilliness, loss of appetite, a craving for juicy fruits or refreshing fruit drinks, perspiration, the sensation of a crushing weight on the top of the head, and dizziness that occurs in the evening, after prolonged standing or when walking. Phos. ac. is suitable for children who grow too quickly and suffer from bone pain as a result, or who are distressed about masturbation and wet dreams.