What is a Diagnosis?
When you go to a doctor with a complaint, the first thing the doctor must do is find out what symptoms you have and what they mean, i.e. make a diagnosis. To do this the doctor will ask you a number of questions and may use some implements to test various parts of your body. Diagnosis requires considerable skill and is a systematic procedure — questions that may seem to you to have little to do with your suffering, such as whether your mother is still alive, are all designed to help the doctor reach a conclusion about what is wrong with you.
Most common illnesses can be diagnosed by the doctor in the surgery, but if specialist knowledge is needed you may have to go to a hospital for further tests. If the doctor requires a sample of your blood or urine to be tested, the sample is sometimes collected by the doctor, but in most cases nowadays you will go to a central clinic staffed by trained nurses, associated with a laboratory.
To make the diagnosis, doctors use a number of diagnostic aids. These include their senses (Do you look pale? Did you walk in with a limp? Was it difficult to lower yourself into the chair?), their knowledge gained during training, their experience, and a wide range of instruments. All these provide information about what is happening inside your body. Some of the tests may be designed to eliminate various possibilities. The doctor will not only try to find out what is wrong but also to assess how far a particular diseases has progressed, what course it may take and therefore what treatment and advice you need, both in the short term and the long term.
The doctor will usually begin by asking questions about your symptoms, what they are, when they started, and whether you have experienced them before. You may be asked whether a member of your family has suffered from the same or a similar ailment. You will probably be asked about your diet, how much you drink and if you smoke. You may be asked what kind of job you do, in particular whether it is sedentary or manual, whether you are under any stress at work or at home, if you play sport and what exercise you get. Your answers to these questions will help the doctor build up a picture of you as a patient and indicate the likelihood of a particular illness.
Following the initial questions, the doctor will usually carry out a physical examination taking a closer look at your body, examining your skin, eyes, tongue and general condition which often reflect a patient's state of health. Your tongue may be pressed down with a spatula so that your throat and tonsils can be seen. Depending on your symptoms, the doctor may take your temperature, and if you are obese or underweight, you may be weighed and measured.
These general observations may be followed with more detailed tests on the different body systems, starting with the one under suspicion. To investigate the circulatory system, the doctor will take your pulse and blood pressure. The blood vessels of your eye may then be examined by pulling down your lower lid. Examination of the vessels on the retina at the back of the eye is done with an instrument called an ophthalmoscope which shines a bright light through the pupil of the eye, and contains a tiny magnifying glass through which the doctor can peer. Diseases of the blood or circulation often become apparent during such eye examinations. Finally the doctor will listen to your heart with a stethoscope and note any abnormal sounds.
The doctor will assess your respiratory system by tapping on your chest and listening to the sound produced. You will be asked to breathe in and out deeply while the doctor listens to your lungs through the stethoscope, first at the front of the body and then at the back.
Apart from looking at the mouth and teeth and examining the anal area, the doctor can examine the digestive system and the internal organs by feeling them through the anal canal or, in women, via the vagina, and by pressing carefully and systematically on the abdominal wall.
Problems in the muscular system usually make themselves evident by means of pain or discomfort when you move. The doctor will check to find out exactly which movements cause pain, e.g. by bending your knee into different positions.
To test your central nervous system, the doctor will ask you to cross your knee, and will then tap below the knee with a small rubber hammer to elicit a jerking reflex response. A similar process is repeated for other reflexes in the knee, elbow and sole of the foot. The doctor will also check your muscle power and tone, look for any muscle wasting or abnormal muscle action, check eye movements, vision and pupil reactions, and may test your memory.
To examine your sense organs, the doctor will look at your eyes with an ophthalmoscope, and into your ears with an auriscope to detect any signs of damage or infection in the middle ear or eardrum. A wide range of tests will also be done to make sure that the senses of touch, pain, temperature and movement or position are functioning as they should.
If a complete diagnosis is impossible, or the doctor wants to confirm a suspected diagnosis, you may need to go for additional tests at a hospital where equipment and specialist knowledge are available.
The role of the hospital in diagnosis ranges from taking X-rays and conducting chemical and microscopic examinations of blood and urine, to scanning with sophisticated and expensive machinery, to performing operations conducted under general anesthetic in which the interior of the body is examined with a lighted tube called an endoscope. The tests will often be carried out by technicians, and the results will be interpreted by specialists.
When the diagnosis has been made, treatment can be decided upon.