The science component involved in medicine is evolving so fast, and over the last couple of decades we have come across many scientific marvels that will make the practice of medicine, safe, pain free, effective and preventive at times. The most important of these are the new diagnostic equipment and techniques like imaging techniques and enhancers, antibody determinants, etc. We are at awe to think how the doctors of the past ever practiced medicine without these. In those days, practice of medicine is more of an art, and the tools used in performing this art are the symptoms and signs. They are still an integral part in the practice of medicine. Now it is important, to avoid the unnecessary investigations being forced upon the patient and make the practitioner capable of doing his craft even in the remotest areas without any equipment.
一种疾病的症状是the complaints the patient will present to the consultation room. These are overt and will be of varying degrees of importance. Some patients will allow for symptoms to fester and will come at a time when it is unbearable, whereas some will come at the first notice of ill feeling. This is based on the personal perception of the patient, and though it is not independent observation, it is very vital in making a diagnosis of the illness the patient might be having. The first step in any consultation is getting the main symptoms and the subsidiary symptoms, and making a proper analysis into them as to when, how long, nature, etc.
标志of an illness are then features which have to be elicited by the practitioner, and this can be done using the most basic of equipments. These signs are not dependent on the perception but have more to do with the progression of the disease. The signs can be assigned as positive and negative signs. The compilation of both of these gives a clear picture as to what the illness. There may be a pathognomonic sign, which clearly gives an inkling regarding the disease. There may be common sign, which need to be supplemented with investigations to make a diagnosis. The eliciting of these signs is done in a systematic pattern, unless you have a set of differential diagnoses, where you can exclude each by looking for specific signs for each.
Both symptoms and signs are used in the process of diagnosis, and there may be inter or intra observer variations in both of these. Both of them vary with time, and when signs are severe, so are the symptoms. Both of these will not be consistent throughout all the stages of life. But it may not be the other way around all the time. And symptoms alone can belie the true situation as there may be patients with psychiatric illnesses with feigning, or dissociative symptoms without signs or malingering. Signs are very much comprehensive and can be a precedent before investigations, where as symptoms require further analysis.
In summary symptoms are medical complaints, which are useful but we cannot put our complete trust into them. Signs on the other hand much better elaborators of the disease entity, and can be used in conjunction with symptoms.