GILBERT R. UPCHURCH, JR., M.D., and TIMOTHY A. SCHAUB, M.D.

Most abdominal aortic aneurysms are asymptomatic. Major risk factors for this type of aneurysm are advanced age, male sex, and smoking 100 cigarettes or more in a lifetime.

Patient information: "Abdominal Aortic Aneurysm (AAA): What You Should Know," p. 1205

Editorial: "Screening and Management of Abdominal Aortic Aneurysm: The Best Evidence," p. 1157

JOSÉ M. PORCEL, M.D., and RICHARD W. LIGHT, M.D.

Pleural effusion, an excess of fluid in the pleural space, can have many different causes. For diagnosis, physicians must determine whether the effusion is a transudate or an exudate.

DOUG NEEF, M.D., and ANNE D. WALLING, M.B., CH.B.

One out of five cases of dementia is believed to result from dementia with Lewy bodies. The emerging consensus is that dementia with Lewy bodies is a distinct pathologic entity sharing features with Alzheimer's disease and Parkinson's disease.

Patient information: "Dementia with Lewy Bodies," p. 1230

BARBARA D. REED, M.D., M.S.P.H.

The diagnosis of vulvodynia depends on a consistent history, lack of a documented infectious or dermatologic cause, and pain when gentle pressure is applied to the vulva, introitus, or hymenal areas. Although evidence for treatment options is limited, several therapies have been used with varying degrees of effectiveness.

Patient information: "Vulvodynia: What You Should Know," p. 1239