An Approach to the DiagnosisChapter 1

It is also known as anamnesis, if the information is provided by patient himself. But if some other person informs about the disease of the patient (e.g. unconscious or uncooperative patient), it is called as heteroanamnesis.

A symptom can be defined as—‘An abnormal feature of a patient which is complained by the patient himself or by his relatives.’ For example: Pain, vomiting, diarrhea, constipation, etc.2

A sign can be defined as—‘An abnormal feature of the patient which is noticed by the physician during his examination.’ For example: Tenderness, fluctuation, crepitation, etc.

Whatever is complained by the patient to the physician cannot always be considered as a symptom. Only logical complaints should be recorded and presented as the symptoms. For example, if a patient says that he is suffering from hernia, it should not be considered as a symptom, as hernia is a diagnosis. Similarly, it is not uncommon to find the patients with palpitation and restlessness complaining the physician that their blood pressure is raised. Here, raised BP cannot be considered as a symptom, as it is a sign which can be detected only by the physician. Some of such unusual presentations of the complaints have been described in Chapter 5.

A physician seeks the diagnosis of disease on the basis of findings of case history and clinical examination of the patient. The first part (history taking) collects the ‘symptoms’ of the patient while the second one (clinical examination) is all about the ‘signs’.

Some symptoms indicate towards abnormalities of a particular system (e.g. hematuria indicates towards diseases of kidney, bladder or urethra). In contrast, some other symptoms (like abdominal pain, fever, etc.) are quite nonspecific and can be the presenting features of a large number of diseases from different systems of the body.

A disease can present with single or multiple symptoms (e.g. abdominal pain, vomiting and fever occur in acute appendicitis). At the same time, a single symptom can be the presenting feature of multiple diseases (e.g. fever can be a presenting symptom of many diseases like malaria, typhoid, dengue, tuberculosis, etc.)3.

A list of diseases which present with similar symptoms is called as the differential diagnosis of that particular symptom. For example, ‘differential diagnosis of right iliac fossa pain’ includes multiple diseases like acute appendicitis, right ureteric colic, acute mesenteric lymphadenitis, Meckel's diverticulitis and many more. Differential diagnosis is commonly mentioned in reference to a symptom, or to a diagnosis. For example, the above mentioned list of diseases can also be called as the ‘differential diagnosis of acute appendicitis’.

As soon as a patient complains of the first symptom to the physician, a list of probable differential diagnoses clicks in his mind. While asking various questions of the case history, a process of assessment runs in his brain simultaneously. It helps him in supporting any one and rejecting the others from the list. As the conversation proceeds, the list of differential diagnoses narrows down. For example, both Buerger's diseases and varicose veins can present with the complaint of chronic pain in lower limbs. Now, while interacting with any such patient, the physician keeps the possibility of both in his mind and seeks more information about his disease and life style. These help him in selecting any one of them as the most probable diagnosis as:

So, even before examining his limb, the physician gets some idea of the probable diagnosis on the basis of information provided by the patient in his history (symptoms). Later on, he confirms it on the basis of findings of clinical examination (signs), and makes a clinical diagnosis of patient's disease.

It is the skill of a physician, which helps him to inquire about various symptoms by interrogating the patient and to detect various signs by conducting his proper clinical examination. By analyzing them together, he can identify what is troubling the patient. This diagnosis which is based only on the findings of 4medical history (symptoms) and clinical examination (signs) is known as ‘Clinical diagnosis’.

Once the clinical diagnosis is made, the physician sends the patient for suitable investigations, if required. The selection of investigations depends on the clinical diagnosis to a great extent. For example, two common acute abdominal conditions, perforation peritonitis and acute appendicitis present with almost similar symptoms (like abdominal pain, vomiting, fever, etc.) but the best diagnostic investigation for a case of perforation peritonitis is plain X-ray chest or abdomen (which shows free gas under diaphragm) while for acute appendicitis it is abdominal ultrasound (which shows inflamed and distended appendix). This selection of appropriate investigation can be made only if the physician has made a correct clinical diagnosis by taking proper case history and by performing appropriate clinical examination of the patient. Otherwise, the patient will be unnecessarily subjected to useless investigations which will increase his financial expenditure.

Many a times, the clinical diagnosis made by a physician may get changed after subjecting the patient to appropriate investigations. Since it is based only on symptoms and signs, and is likely to be changed in future, it is also known as ‘Provisional diagnosis’ of the disease. (Dictionary meaning of provisional: Arranged or existing for the present, likely to be changed later.)

The diagnosis which is made on the basis of reports of various investigations, which are done before (e.g. blood tests, sputum examination, etc.) or after (e.g. biopsy) giving the appropriate treatment (e.g. surgery) to the patient is known as ‘Final diagnosis’ or ‘Definitive diagnosis’. For example, in the above mentioned case of abdominal pain and tenderness in right iliac fossa:

The major task of a medical student is to make a clinical diagnosis on the basis of signs and symptoms. Beyond this, he can neither advise any investigation nor prescribe any treatment to the patient. However, he should have a proper theoretical knowledge of the investigations and treatment part of the disease. So, during his clinical training period, a student should mainly focus on developing skills of interrogating (for symptoms) and examining (for signs) the patients with different diseases.

Examination of a patient can only show the abnormalities present at the time of examination. On the other hand, his case history can also reveal multiple other aspects which are related to the development of his disease. For example, a gynecologist could not find anything abnormal in general, systemic and gynecological examination of a female presenting with infertility. But when she revealed a history of tuberculosis in her past, he started suspecting a diagnosis of tubercular salpingitis, which is a common cause of female infertility in our country.

In short, the act of history taking is helpful to a physician in following ways:

A patient is always serious while selecting the suitable doctor for his disease as he knows that his wellness and life will be in his hands. In present era, due to the advancement of medical science, every city of our country has a large number of doctors from every specialty. This pool will keep on expanding in the future also. Nowadays, the patients have got multiple options for treatment of any disease; ranging from economic to expensive and from experienced to young doctors. Along with so many other criteria, the behavior of the doctor also plays a major role in this selection. A doctor who is gentle and confident in his communication will certainly gain the faith of the patient and fame in his practicing 7area. One the other hand, a doctor with perfect knowledge and skill of his specialty may fail to succeed in his practice if he is not looking confident during communication with his patients. In such a case, the patient will never hesitate in switching over to some other doctor for treatment of his disease.

Theoretical knowledge and clinical skills of any doctor can be compared to some cereals (like rice or wheat flour). By virtue of his knowledge alone he can prepare some nutritious dish but that will not be palatable. Hence, he needs the spices of communication skills also. Only a proper combination of knowledge (cereals) and communication skills (spices) will lead to a nutritious and palatable recipe.

There is no single, standard format which can be used for all types of patients in all over the world. For instance, there is a significant difference between format used for gynecological patients and that for psychiatric patients. While Menstrual and obstetric history is stressed more for a gynecological patient, Personal history will be a major section while interrogating a psychiatric patient. Besides, there can also be some regional variation in importance of several questions. For example, the history of tuberculosis is quite important for a patient in India but it is not of much importance for every patient in UK. Conversely, a physician can frankly ask about the sexual history to an adolescent girl in the western world but the same enquiry should be done more cautiously in our country.8

There may be minor variations amongst the formats from different sources. The format which will be utilized in this book for a detailed description of medical history is presented in Chapter 3.

In other words, for any disease, all the questions of the standard format of history can be broadly divided in ‘very important’, ‘important’ and ‘unimportant’ categories, from the point of view of their relative significance in diagnosis and management of the disease. For example, in case of a patient presenting with hematemesis, history of addiction (alcohol) will be very important, dietary history (spicy diet) will be important but residence, sleep, marital status, etc. will be relatively unimportant questions to be asked. On the other hand, in case of a female presenting with a painless lump in her breast, enquiry of family history will be very important, her menstrual and obstetric history will be important while many other points like religion, occupation, addiction, etc. will be comparatively unimportant for making diagnosis and treatment plan for her disease.

As a part of his medical training, every student is expected to ask all the questions to all the patients. Moreover as he is in early stage of learning, it is difficult for him to confidently decide the relative importance of various questions for various diseases. But at the same time, he should start learning about this type of segregation of questions in early stage. It would help him in categorizing the questions in his future life. It may be difficult for him initially, but gradually, with increasing theoretical and clinical knowledge, he will be able to select the relatively important questions for different diseases9.

No one can make a standard way by which all the questions can be asked to all types of patients. The appropriate method of asking a question to a patient depends on his or her age, gender, education and socioeconomic status. For example, a 20 years old female from an urban area and a 60 years old male from some rural area present with the features suggestive of renal stone. Despite the fact that both are having the same disease, there will be a significant difference is the way of asking them the relevant questions. The girl can be asked in a straight forward manner using sophisticated urban accent and even English words and phrases. On the other hand, questions asked in this manner will not be properly understood by the illiterate old man, and so, he should be asked the same questions in a totally different way.

This book is mostly focused on answering the same question—How to ask?. It will guide the students and doctors to the most practical way of asking a particular question of medical history from the patients of different age, sex and socioeconomic status. This knowledge will definitely improve their confidence while interacting with various types of patients, and that will lead to a more successful session of communication with the patient.

Apart from these three, there is one additional pillar of ‘how to interpret?’, which is more important in clinical practice than during student life. A practicing physician asks only the relevant questions to his patients. Also, he interprets the information provided by the patient cautiously and selects only those information which can be directly correlated to his disease. For example, an elderly patient presented with a soft, painless swelling at his shoulder region since few months. When the student asked about his personal history, he informed him about decreased sleep, loss of appetite and some weight loss in last few 10years. Now, a medical student will note down and present all of these information. But, a practicing physician will not give much importance to them. They are more likely to be the physiological changes associated with old age, and so, they cannot be correlated with a swelling which is more likely to be benign in nature (e.g. lipoma). Theoretical knowledge of various diseases, along with the clinical experience, helps a practicing physician in deciding about ‘how to interpret’ various information provided by the patients.

I often call it as a matter of 30 minutes v/s 3 minutes. A student may need 30 minutes to interrogate and examine a patient while the same task can be done by a practicing doctor in only 3 minutes.12

Many diseases present with almost similar signs and symptoms. So, this shift in diagnosis is a common phenomenon in routine clinical practice and even expert doctors are not always successful in making an accurate clinical diagnosis. Hence, before planning patient's definitive treatment, it is always better to get the relevant investigations done, if required. For example, in the above mentioned case, though both appendicitis and ureteric stone can present with similar signs and symptoms, their management is completely different from each other. Appendicitis needs an urgent surgical intervention (open or laparoscopic) while ureteric stones are mainly managed either by conservative treatment 13or by endoscopic procedure. If the surgeon has made a wrong clinical diagnosis and has not confirmed it with appropriate investigations, further treatment will lead in a wrong direction and can be hazardous for the patient.

So, it is needless to say that investigations play an important part in the management of any disease. But at the same time, one should not forget that the investigations are only supplementary to a proper clinical diagnosis. Selection of appropriate investigation largely depends on the provisional diagnosis of the disease as described earlier in this chapter. A patient should be referred for the investigations only after taking a proper history and clinical examination. It would be a wrong method to send the patient for investigation directly without seeking the signs and symptoms of his disease.

A good physician always makes some provisional diagnosis before sending the patient to relevant investigations. But, some others avoid it and directly send the patient for the series of investigations. For example, a patient with abdominal pain was advised for ultrasonography by the surgeon without doing a proper abdominal examination. Similarly, a patient with cough and breathlessness was straightway sent by the physician for an X-ray chest without performing a proper clinical examination of respiratory system. Once the patient comes back with the investigation reports, it becomes easier for them to make a diagnosis retrospectively. There can be several reasons behind this approach. Some may be afraid of making and writing a wrong provisional diagnosis on patient's case sheet. This fear is usually seen in postgraduate students in OPD and clinical practitioners in early stages. Excessive bulk of the patients may be another reason which may prevent some doctors from performing proper interrogation and examination of the patient. No doubt that it looks like an easy and accurate method of diagnosing various diseases. But, in a long run, this habit may deteriorate the communication and examination skills of physician for various types of patients.

There is no substitute of proper history taking and clinical examination of the patient before sending him for investigations. Excessive dependency on investigations can be hazardous in the following ways:

The knowledge and skill of making appropriate clinical diagnosis also helps the physician in challenging the investigation report (both false positive and false negative) in some cases. For example: