Despite the importance of daily symptoms for people's quality of living, they are seldom studied (thus, the "iceberg of morbidity"). We begin by reviewing United States and British studies that have information on daily symptoms experienced by adults. The most common ones are respiratory (largely from colds) and musculoskeletal (largely from arthritis, injury, overexertion). Using health diaries kept for 6 weeks by a population-based sample of adults, we report the frequency of respiratory and musculoskeletal symptoms, their specific types and causes, and what factor urge people to take therapeutic actions for them. The most popular action for both is prescription or nonprescription drugs, followed by lay consultation, then restricted activity, and lastly seeking medical care. On Respiratory Days, how miserable a person feels is the main stimulus to action; other morbidity aspects of the day also rank high. Sociodemographic groups scarcely differ in their responses to respiratory symptoms. The situation is similar for Musculoskeletal Nondisease Days (injury/overexertion). But for Musculoskeletal Disease Days (arthritis), sociodemographic characteristics figure more strongly in care, and the day's degree of morbidity less. These results signal basic differences in how people approach chronic and acute health problems: For chronic ones, they devise strategies of care (determined partly by their roles, attitudes, and resources) over months and years, and apply them during flare-ups. For acute problems, decisions about care are made in the short run and hinge mostly on symptoms. Our analysis also considers how actions complement or substitute for each other: Self-care actions (nonprescription drug use and restricted activity) tend to co-occur, and so do actions based on medical care (prescription drug use and medical contact). The two domains substitute in one way (nonprescription drug use greatly reduces chances of prescription drug use) and join in another (restricted activity increases chances of medical contact).