Spearmint is used for digestive disorders including gas, indigestion, nausea, diarrhea, upper gastrointestinal tract spasms, irritable bowel syndrome (IBS), bile duct and gallbladder swelling (inflammation), and gallstones.It is also used for sore throat, colds, headaches, toothaches, cramps, cancer and inflammation of respiratory tract. Some people use it as a stimulant, germ-killer, local pain-killer, and anti-spasm medication. Spearmint is applied directly to the skin for swelling inside the mouth, arthritis, local muscle and nerve pain, and skin condition.