A century ago, about the only means a doctor had to diagnose a patient were to take his pulse, listen to his lungs and heart through a stethoscope and probe his body with a few taps and palpations. Today, there are hundreds of diagnostic tests that quantify a person's health with numbers, images and graphs. Critics claim that modern doctors have "lost the touch" for detecting illness by touching their patients, and instead send them for superfluous, costly and sometimes risky tests to safeguard themselves against lawsuits. But there is no doubt that these sophisticated, mostly computerized tests have advanced early diagnosis and treatment of disease and helped to extend life expectancy. Yet doctors are pressed to see more patients every day, and often lack the time to explain test purposes and procedures, leaving patients confused and nervous. Dr. Itzchak Levy, director of the AIDS and venereal disease service at Sheba Medical Center and medical editor of the Infomed Web site, has just produced an excellent guide to these procedures. The 344-page Hebrew-language volume titled Bedikot: Hamadrich Hashalem (Medical Tests: The Complete Guide) is the first Hebrew guide of its kind, and will be very helpful not only to patients but also to doctors. Published by Yediot Sefarim, the volume explains some 300 tests in detail. It costs NIS 128, but the information inside is worth its weight in gold. The book, with indexes in both Hebrew and English, is in the same format as Levy's previous medications "bible" called Hatrufot: Hamadrich Hashalem. The author notes in the beginning that the book with help readers prepare intelligent questions for their doctors and nurses, but of course advises them to consult their physicians for further information. If the medical system had unlimited funds, one could send every patient for all 300 tests, just to be sure he is disease free or to catch an illness before symptoms present themselves, notes Levy in the introduction. But this is only theoretical, as some tests produce false positives (in which you are shown to have a problem that doesn't exist) and false negatives (in which you have a condition but the test misses it). Some tests determine whether a patient has a condition (such as being an HIV carrier), while others identify risk factors such as high blood cholesterol, hemoglobin, glucose or genetic markers for diseases. Some tests are used to monitor diagnosed disorders and assess the efficacy of drugs being taken for them. While many patients ask their doctors for a routine blood or urine test "just to make sure the results fall within acceptable limits," medical tests should not be used like a tranquilizer, as they all cost money and can cause unnecessary anxiety, Levy continues. The World Health Organization and others recommend only a handful of screening tests to detect diseases such as breast, cervical, prostate and colon cancer, hypertension and diabetes. Sometimes only a few drops of blood from a finger are needed, but in most cases, a half a test tube of blood from the inside of the elbow is needed. Sometimes one needs to fast before the test, and other times there is no such need. Urine also provides a window on health by testing its various components, including creatinine, uric acid, urea, potassium and sodium. There are nearly 100 other components in urine, each in minute amounts that can point to disorders. Many people don't even know how to produce an optimal urine sample: Levy explains that the plastic cup should collect only midstream flow and not the first urine produced, as initial flow may contain other components that could affect the results. Other bodily fluids tested include tears, saliva, sweat, spinal fluid, semen and vaginal fluids. Undergoing scans of the whole body or part of it by computerized tomography (CT) or magnetic resonance imaging (MRI) is usually not painful, but a biopsy of live tissue is invasive and can be unpleasant. Results of tests on children and pregnant women, the author notes, are usually quite different than those of other patients, and kids have to be prepared ahead of time. There is a large variety of tests for the nervous system, heart, immune system, lungs, blood vessels, reproductive system, eyes, ears, skin and throat. Levy describes each of these, what can go wrong, and how specific tests are helpful in diagnosing problems. Some 300 pages are devoted to the tests themselves, with one to a page. They are listed in various sections: hematology and clotting; chemical tests on blood and other body fluids; the brain and nervous system; the respiratory system; the cardiovascular system; the digestive system; muscles, bones and joints; the immune system and allergies; infectious diseases; metabolism, hormones and the internal elimination system; blood fats; the reproductive system; pregnancy; urinary system; vision; hearing; genetic disorders; cancers; medications and drugs; imaging and nuclear medicine; and vital signs. A dictionary of important terms from "sensitivity" to "histology" is provided. The book conveniently provides test names in English as well as Hebrew, along with warnings about the special influences of pregnancy, breastfeeding, old age, alcohol, driving and young age on the results. Also included are explanations of how much material is needed for each test; how urgent it is for the sample to be tested in a lab; if the test poses any risk; if one has to fast beforehand; if it is routinely prescribed; and if there are any conditions that preclude testing. Black-and-white illustrations appear on some of the pages. The guide also includes abbreviations for tests as listed on lab printouts, such as EOS for eosinophils, which are a type of white corpuscles in the blood, or BAS for basophils, another type of white cells that contain histamine and are involved in allergies. Some of the test names are well known, but you will probably never encounter others, such as "anti-glomerular basement membrane Ab," "cryoglubulins" or "hysterosalpingography." This book should be in every Hebrew-speaking home, especially those of families that prefer to take an active part in promoting and preserving their health rather than just leaving it to their general practitioner. The only caveat is that it is not recommended for hypochondriacs.