In medicine, devices are sometimes necessary to create suction

Suction

Suction is the flow of a fluid into a partial vacuum, or region of low pressure. The pressure gradient between this region and the ambient pressure will propel matter toward the low pressure area. Suction is popularly thought of as an attractive effect, which is incorrect since vacuums do not...

. Suction may be used to clear the airway

Airway

The pulmonary airway comprises those parts of the respiratory system through which air flows, conceptually beginning at the nose and mouth, and terminating in the alveoli...

 of blood, saliva, vomit, or other secretion

Secretion

Secretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland. In contrast to excretion, the substance may have a certain function, rather than being a waste product...

s so that a patient may breathe. Suctioning can prevent pulmonary aspiration

Pulmonary aspiration

Pulmonary aspiration is the entry of material from the oropharynx or gastrointestinal tract into the larynx and lower respiratory tract...

, which can lead to lung infections. In pulmonary toilet

Pulmonary toilet

Pulmonary hygiene, formerly referred to as pulmonary toilet, is a set of methods used to clear mucus and secretions from the airways. The word pulmonary refers to the lungs...

, suction is used to remove fluids from the airways, to facilitate breathing

Breathing

Breathing is the process that moves air in and out of the lungs. Aerobic organisms require oxygen to release energy via respiration, in the form of the metabolism of energy-rich molecules such as glucose. Breathing is only one process that delivers oxygen to where it is needed in the body and...

 and prevent growth of microorganisms.

In surgery

Surgery

Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...

 suction can be used to remove blood from the area being operated on to allow surgeons to view and work on the area. Suction may also be used to remove blood that has built up within the skull after an intracranial hemorrhage

Intracranial hemorrhage

An intracranial hemorrhage is a hemorrhage, or bleeding, within the skull.-Causes:Intracranial bleeding occurs when a blood vessel within the skull is ruptured or leaks. It can result from physical trauma or nontraumatic causes such as a ruptured aneurysm...

.

Suction devices may be mechanical hand pumps or battery or electrically operated mechanisms. The yankauer suction tip

Yankauer suction tip

The Yankauer suction tip is an oral suctioning tool used in medicine. It is a suction tip with a large opening surrounded by a bulbous head and is designed to allow effective suction without damaging surrounding tissue. This tool is used to suction oropharyngeal secretions in order to prevent...

 is one type of tip attached to a suction unit. Another is the Frazier suction tip.