This book describes the diseases that are most frequently encountered during general medical consultation. The discussion of each condition includes the following: Introductory paragraph. This section summarizes the condition, its definition, main clinical characteristics, and epidemiology, as a quick guide for the doctor regarding the specific disease, the type of people who may suffer from it, and its prognosis. Etiopathogenesis. Here, the causes of the disease are explained in a simple and concrete manner to give the doctor a clearer picture of the pathology of the disease. Signs and symptoms. In this section the most significant characteristics of the disease are described, which makes it possible to identify and differentiate the disease from other similar ones. Diagnosis. This section provides the key information to establish the diagnosis of each condition. In most cases, the clinical information is explained in such a way that neither laboratory nor office testing will be required. Treatment. This section contains a concise listing of the most effective, current, accessible, and least toxic drugs to treat the disease, together with dosages for adults and children (where applicable), in addition to the length of time that the drug should be taken. Almost all of the drugs described are available in generic form, which is an important economic consideration for the patient. In Mexico and many other countries, the quality of these products is verified by bioequivalence tests to compare the activity of the patent drug with the generic one. Most physicians need to prescribe fewer than 100 different drugs for their various patients. Therefore, it is much more important, especially in terms of patient safety, that the doctor have in-depth prescription information about a few drugs, than to know a little about a wide range of drugs that he/she may never have the opportunity to prescribe.