Signs and symptoms Contents

Development of medical testing[edit]

Further information: Medical test
Painting of René Laennec in 1816 using an early method of auscultation on a man with tuberculosis.

A number of advances introduced mostly in the 19th century, allowed for more objective assessment by the physician in search of a diagnosis, and less need of input from the patient.^[41][42][43] During the 20th century the introduction of a wide range of imaging techniques have made a huge impact on diagnostic capability. Other developments in the field of genetics, medical biochemistry, and molecular diagnostics have also played major roles.

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  In 1761 the percussion technique for diagnosing respiratory conditions was discovered by Leopold Auenbrugger.^[44] This method of tapping body cavities to note any abnormal sounds had already been in practice for a long time in cardiology.^[44] Percussion of the thorax became more widely known after 1808 with the translation of Auenbrugger's work from Latin into French by Jean-Nicolas Corvisart.^{[citation needed]}
  

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  In 1819 the introduction of the stethoscope by René Laennec began to replace the centuries old technique of immediate auscultation – listening to the heart by placing the ear directly on the chest, with mediate auscultation using the stethoscope to listen to the sounds of the heart and respiratory tract. Laennec's publication was translated into English, 1821–1834, by John Forbes^{[citation needed]}
  

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  The 1846 introduction by surgeon John Hutchinson (1811–1861) of the spirometer, an apparatus for assessing the mechanical properties of the lungs via measurements of forced exhalation and forced inhalation. (The recorded lung volumes and air flow rates are used to distinguish between restrictive disease (in which the lung volumes are decreased: e.g., cystic fibrosis) and obstructive diseases (in which the lung volume is normal but the air flow rate is impeded; e.g., emphysema).)^{[citation needed]}
  
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  The 1851 invention by Hermann von Helmholtz (1821–1894) of the ophthalmoscope, which allowed physicians to examine the inside of the human eye.
  
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  The (c. 1870) immediate widespread clinical use of Sir Thomas Clifford Allbutt's (1836–1925) six-inch (rather than twelve-inch) pocket clinical thermometer, which he had devised in 1867.^[45]
  
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  The 1882 introduction of bacterial cultures by Robert Koch, initially for tuberculosis, being the first laboratory test to confirm bacterial infections.
  
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  The 1895 clinical use of X-rays which began almost immediately after they had been discovered that year by Wilhelm Conrad Röntgen (1845–1923).
  
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  The 1896 introduction of the sphygmomanometer, designed by Scipione Riva-Rocci (1863–1937), to measure blood pressure.
  

Diagnosis[edit]

The recognition of signs, and noting of symptoms may lead to a diagnosis. Otherwise a physical examination may be carried out, and a medical history taken. Further diagnostic medical tests such as blood tests, scans, and biopsies, may be needed. An X-ray for example would soon be diagnostic or not of a bone fracture. A noted significance detected during an examination or from a medical test may be known as a medical finding.^[46]