About 10% of the public will develop a peptic ulcer during their lifetime. The prevalence in our part of the world is gradually getting smaller, the prevalence is higher in third world countries. This is even more so for ulcers located to the duodenum. The living-standard in the western world prevents transmission of Helicobacter pylori, this is the cause of this development.
Peptic ulcers are about as common in females (9,5%) as in men (10,5%) according to a Norwegian study (Sørreisa-studien, 1992). Ulcers in the duodenum is most frequent in the agegroup 30-55 years, while stomach-ulcers are more common in the agegroup 55-70 years.
About 20-50% of the population is infected with the Hp-bacteria. The prevalence of the infection rises with advancing age. A peptic ulcer only develops in 15-20% of those with an Hp-infection. This means that an infection with the bacteria is not enough for you to develop neither peptic ulcers or a malignant tumor. Only a small fraction of the infected population develop ulcers or tumors.