 A psychosomatic component is often inferred when there are some aspects of the patient's presentation that are unaccounted for by biological factors, or some cases where there is no biological explanation at all.For instance, "Helicobacter pylori" causes 80% of peptic ulcers.However, most people living with "Helicobacter pylori" do not develop ulcers, and 20% of patients with ulcers have no "H. pylori" infection.