Auscultation is a procedure that involves listening to sounds within the body, using a stethoscope, to assess the functioning of an organ or to detect disease.
Auscultation of the heart
To listen to the heart, the doctor places the stethoscope on the chest at four points which correspond to the location of the heart valves.
Auscultation of the lungs
When listening to the lungs, the doctor places the stethoscope on numerous areas of the chest and back. The patient breathes normally, and then takes deep breaths, so that the doctor can compare the sounds on the right and left sides. Abnormal breath sounds may indicate pneumonia, bronchitis, and pneumothorax (in which air enters the space between the pleura, the membranes lining the outside of the lungs and the inside of the chest cavity).
Cracking or bubbling sounds (known as crepitations) are caused by fluid in the lungs; wheezing sounds result from spasm of the air ways, usually as a result of asthma Pleurisy (inflammation of the pleura) causes a scratching sound as inflamed areas of the lung rub together.
The doctor may also test for vocal resonance by asking the patient to whisper something. The sound is louder if there is pus in the lung due to a condition such as pneumonia.
Auscultation of the blood vessels
Blood vessels near the skin surface (usually the carotid artery in the neck, the abdominal aorta, or the renal artery) may be listened to for bruits (sounds made by turbulent or abnormally fast blood circulation). Bruits occur when blood vessels are narrowed (for example). They may also be present if heart valves have been narrowed or damaged (for example by endocarditis).
Auscultation of the abdomen
The abdomen is auscultated for the borborygmi (loud rumbling, gurgling sounds that are made by the movement of air and fluid in the intestine), and also for abnormal bowel sounds that may indicate intestinal obstruction.