Medical journalist Lawrence Galton, who's also written about old age, heart attacks, hypertension and backaches, calls anemia ""the stunningly common problem""--especially among children, the elderly, pregnant women, and the inadequately nourished in general. The World Health Organization estimates that one-fifth of the population suffers from garden-variety iron-deficiency anemia. But Galton also covers a number of the more exotic kinds--from the symptoms associated with pica (strange cravings for clay, dirt, ice, lead) or alcoholism or chronic trauma, to Rh or pernicious anemia, vitamin and folic-acid deficiencies (the last is sometimes caused by the Pill). The section on sickle-cell anemia explores the disease's etiology and debunks the notion that it's solely confined to blacks. Galton deplores the medical profession's tendency to shotgun therapy without a careful diagnosis, and, of course, all those ""tired blood"" placebos. A responsible survey.