Diagnostics is a purposeful medical search that allows you to judge the patient’s state of health, the presence or absence of diseases. The result of the diagnosis is the formulation of a medical diagnosis – the interpretation of the results obtained and the preparation of an expert opinion. Instrumental diagnostics complements and clarifies the data of anamnesis, physical examination, laboratory tests. Instrumental diagnostic methods are widely used in various fields of medicine. Functional, radiological (ultrasound, X-ray, CT, PET, MRI, scintigraphy), endoscopic methods, minimally invasive studies are of the greatest diagnostic value
Diagnosis is the next stage of the patient’s curation after the medical consultation. The importance of fast and accurate diagnostics in medicine is difficult to overestimate. At the same time, a competent diagnostic search is the most important task for any clinician, since all further treatment, prognosis and prevention of the disease depend on a correct diagnosis. No wonder the ancient healers noted: “Diagnosis bona – curatio bona” – “A good (correct) diagnosis is the key to good treatment.” In a broad sense, diagnostics can be aimed not only at identifying a particular pathology, but also a number of physiological conditions (pregnancy, menopause, etc.). The modern preventive direction of diagnosis is “Check-up” – a comprehensive clinical examination performed in the shortest possible time (usually within a few hours) and giving a complete picture of the state of health.
All types of modern diagnostics used in various fields of medicine can be divided into the following groups:
- anamnesis collection (questioning of the patient)
- physical examination is a diagnosis carried out by a doctor using the senses (includes examination, percussion, palpation, auscultation)
- laboratory and instrumental studies.
Listening to complaints and questioning the patient are among the most historically ancient diagnostic techniques. Meanwhile, these methods can give a lot of important diagnostic information to an experienced clinician. So, until now, it is believed that in the diagnosis of angina pectoris, anamnestic data surpass in value a number of objective indicators of heart research. The subjective feelings of the patient are nothing more than symptoms, which form the overall picture of the disease.
First, the doctor listens to the complaints of the patient himself, then with the help of questions he finds out the details that interest him. When collecting anamnesis, a specialist evaluates the time and sequence of the appearance of certain symptoms, changes in their nature and intensity as the pathological process unfolds. Next, the doctor is interested in where the patient went with this problem, what treatment he received earlier, and what was its effectiveness. In addition to the picture of a specific disease, the doctor may be interested in the patient’s life history – information about previous illnesses, surgical interventions and injuries, heredity, hypersensitivity reactions, etc. Special attention is paid to the living and working conditions of the patient, as well as bad habits that could cause this disease.
In various fields of practical medicine, there is an algorithm for collecting anamnesis. So, when examining a child, the pediatrician will be interested in the age of the parents; from which pregnancy and childbirth the baby was born, and how they proceeded; the type of feeding, the physical and psychomotor development of the child, the diseases suffered, the timing of teething, etc. Having answers to these questions, a pediatrician may suspect some congenital diseases, mental development disorders, and also assess the risks of pathology in the future.
During the diagnosis in gynecology, the patient finds out the age of menarche and the beginning of sexual life, the number of sexual partners, the number of pregnancies and childbirth (or the reasons for termination of pregnancy – miscarriage, abortion, stillbirth), gynecological diseases suffered.
Anamnesis collection plays a primary role in the diagnosis of infectious diseases. The task of an infectious disease doctor is to establish the source of infection, transmission factors and the mechanism of infection. For example, parenteral manipulations and operations preceding the appearance of jaundice, blood transfusions allow us to think about viral hepatitis B. If the patient ate home-canned food shortly before the onset of the disease, there is an assumption that he has botulism. A recent visit by a sick person to an area endemic for a particular infectious disease allows for further diagnostic search in a certain direction.
After the survey is completed, a physical examination of the patient with an assessment of the objective status is performed as part of the initial consultation.
Physical examination, or objective diagnosis, begins with a general examination, paying attention to the general condition, position, consciousness of the patient, his physique and constitution, the color of the skin and visible mucous membranes. Then the part of the body and the area to which the complaint relates are examined directly. Special examination methods are used in gynecology (examination on a chair with mirrors), dermatology (dermatoscopy, luminescent diagnostics), otolaryngology (examination of the throat with a frontal reflector and a spatula, examination of the eardrum with an ear funnel), dentistry (examination of teeth with a dental mirror and probe) and other areas of practical medicine.
After an external examination, a post-systemic examination is performed (examination of the musculoskeletal, cardiovascular, respiratory, digestive, urinary, endocrine and nervous systems, sensory organs). Here, in addition to external examination, the specialist uses such primary diagnostic methods as auscultation, percussion and palpation.
Auscultation (listening) of sounds arising from the functioning of various organs is performed using a phonendoscope at special projection points on the surface of the body. Auscultation is most informative when examining the heart and large vessels, lungs, abdominal organs. Thus, auscultation of the lungs allows us to assess the nature of the main and secondary respiratory noises, various sound phenomena inherent in a particular disease. Auscultation of the heart gives an idea of the heart tones, heart rate, heart murmurs. Abdominal auscultation is mainly aimed at assessing intestinal peristalsis. On the basis of auscultative data, it is possible to detect pneumonia, heart defects, intestinal obstruction, and other pathology.
Percussion (tapping) of any part of the body is used to determine the boundaries of internal organs and their physical condition. Percussion is most often used in the examination of the lungs, heart, liver. By changing the characteristics of the normal percussion sound, the clinician can judge the presence of a particular pathology.
Palpation is a feeling of various areas of the body. By palpation, the organs of the abdominal cavity and pelvis, mammary glands, lymph nodes are examined, assessing their location, size, shape, consistency, soreness. Special methods of palpation are used in gynecology (bimanual examination), urology and proctology (prostate palpation, finger examination of the rectum).
The preliminary diagnosis established on the basis of an objective diagnosis is further confirmed or refuted using instrumental and laboratory methods.
Laboratory and instrumental studies
Discoveries in biology, microbiology, chemistry, physics, genetics and other scientific disciplines have given impetus to the development of instrumental laboratory diagnostics. All laboratory tests can be divided into standard / general (required for the diagnosis of a wide range of diseases) and special (used to confirm certain nosologies). General laboratory tests include clinical blood and urine tests, blood biochemistry. Special diagnostic studies may include microbiological crops (sputum, urine, breast milk, blood, feces, wound discharge, etc.), PCR, ELISA, IFA, determination of cancer markers, hormones, etc.
Instrumental diagnostics has the greatest objectivity and diagnostic value. Currently, such research methods as X-ray, ultrasound and endoscopic diagnostics, functional diagnostics, radionuclide studies, computer and magnetic resonance imaging have become routine.
X-ray diagnostics are among the most historically early, but have not lost their significance at the same time. With the help of X-rays, it is possible to study the anatomical characteristics and function of almost any organ. The image of the object under study can be obtained in the form of a film or digital image (radiography) or as a picture on a fluorescent screen (fluoroscopy). Vessels (angiography), skeleton (radiography of bones, joints, spine), internal organs (radiography of the thoracic and abdominal cavities, genitourinary system), soft tissues can be subjected to X-ray examination.
Perhaps there is no such section of clinical medicine in which ultrasound examinations would not be used. Modern diagnostic protocols in obstetrics and gynecology, gastroenterology, mammology, cardiology, urology, surgery, pediatrics are unthinkable without them. Ultrasound makes it possible to detect a wide range of pathological changes in superficially located tissues and internal organs that are inaccessible to eye examination. In this case, a two-dimensional image can be transformed into a three-dimensional one (static 3D mode or dynamic 4D mode). Dopplerography is used to study the vascular bed of any localization and caliber.