130 READINGS IN BIOLOGICAL SCIENCE 



pressure, the first thing he will do is to ask you to describe your symptoms. 

 Symptoms are indications of trouble, like pain, which only you can feel. 

 As they give the doctor important information about you, it is essential 

 that you describe them honestly and carefully. The doctor will then pro- 

 ceed to look for signs of trouble — things which he himself can detect 

 with the help of various instruments and tests. 



CHECKING UP ON YOUR BLOOD PRESSURE 



In taking your blood pressure your physician will measure the amount 

 of pressure exerted by the blood against the main artery of your arm at the 

 peak of the heart beat (systole) and at the pause between beats (diastole). 

 The apparatus the doctor uses is famihar to almost everyone because blood 

 pressure is now measured in the course of practically every m.edical exam- 

 ination, although this procedure came into general use only a generation 

 ago. 



If necessary, the doctor will also examine the interior of your eyes with 

 an instrument called an ophthalmoscope, which enables him to see the mi- 

 nute blood vessels at the back of the eye. Since these blood vessels are 

 similar to those in other less accessible regions of the body, the ability to 

 observe them directly gives the doctor an idea of how good your blood 

 vessels are. From an analysis of your urine (urinalysis), and perhaps by 

 other tests of kidney function, your doctor will gain valuable information 

 about the condition of your kidneys. This knowledge is important be- 

 cause high blood pressure or hypertensive heart disease is sometimes as- 

 sociated with kidney disease. 



CHECKING UP ON YOUR HEART 



Usually the physician first feels (palpates) and taps (percusses) the 

 cardiac region of the chest to determine the position, size, and shape of 

 your heart. In addition, he may ask you to stand behind the screen of a 

 fluoroscope while he studies the shadow of your heart cast by X-rays on 

 the screen. To have a permanent record for further study and future com- 

 parison, he may also have an X-ray picture taken. 



By listening to the sounds made by your heart in action through a 

 stethoscope, which magnifies them, the doctor is able to detect "murmurs" 

 or other deviations from normal. Heart murmurs are gentle, blowing 

 sounds which may or may not indicate that something is wrong with the 

 heart. A great many murmurs have little or no importance. Others may 

 indicate that damage has been done to the valves or heart muscle as a 

 result of rheumatic heart disease or some other condition. 



The physician may also wish to have an electrocardiogram made. This 

 is a written record of the electrical activity which sweeps down and over 

 your heart at each heart beat. The sensitive apparatus that does the writing 

 at the dictation of the heart is called an electrocardiograph. The physician 



