Final answer:
Gallstones are solid particles that form in the gallbladder due to cholesterol accumulation. While the specific incidence for persons over 65 is not provided, heart disease is a common health issue in this age group.
Step-by-step explanation:
Gallstones are solid particles that form in the gallbladder when a large amount of cholesterol accumulates. They can be made up of almost 100% cholesterol with small amounts of calcium salts, glycerophospholipids, and fatty acids. Small gallstones can pass through the bile duct and be excreted, but large gallstones can get stuck and cause pain and jaundice.
The incidence of gallstones in the United States for persons over 65 years of age is not specified in the provided information. However, according to a study by the Administration on Aging, heart disease was reported in about 32% of people over 65. While gallstones are not specifically mentioned, it is worth noting that they are a common condition, particularly in older adults.