When it comes to the manner by which they are done, medical procedures are classified into two general types - the non-invasive and the invasive medical procedures.
The non-invasive medical procedures refer to those types of procedures that are carried out without creating a break or incision in the skin; or when no contact with the mucosa or any internal body cavity is made. By definition, deep palpation, percussion, and eardrum examination would be considered non-invasive, just like wound cleaning and dressing, and blood pressure reading using mercury or a digital sphygmomanometer.
An invasive medical procedure on the other hand, refers to a type of procedure that involves invasion of the internal body by making a break or incision in the skin, or by inserting a tube or a device into an internal body cavity or organ. Unlike non-invasive medical procedures, the invasive types can only be performed after an informed consent has been duly signed by the patient himself, the spouse, or the parent of a minor who will undergo an invasive medical procedure. It is the responsibility of the health care provider to provide the patient and his family a thorough explanation regarding the medical procedure he is about to undergo, including its associated benefits and risks.
A type of invasive procedure that causes slight damage to biological tissues at the point of incision or insertion of a medical device or instrument is called a minimally invasive procedure.
Just like the non-invasive types, invasive medical procedures can be categorized into two according to their purpose, such as follows:
Invasive Diagnostic Procedures
An invasive medical procedure that is done to investigate the condition of a certain organ or to confirm a suspicion of an underlying disease is called an invasive diagnostic procedure. These invasive procedures are carried out to establish a medical diagnosis, such as the presence of cancers, a heart disease, or any other health condition.
Cardiac catheterization, an umbrella term for a group of invasive tests to examine the function and condition of the heart, is among the typical invasive procedures used for diagnosis. The most common type of cardiac catheterization is the angiography (angiogram) which involves the insertion of a fluorescent-labeled hollow tube into the heart's blood vessels to determine their condition.
Other classic examples of invasive diagnostic procedures include: endoscopy, the insertion of a very flexible tube with a lens or a camera and a light on the end, which is attached to a computer screen to allow the doctor to see the interiors of a hollow organ, like the uterus or the intestines. Tissue samples for biopsy can also be obtained using the endoscopic tubes. Other invasive procedures used to establish diagnosis include Pap's Smear, trans-esophageal echocardiography, trans-vaginal or trans-rectal ultrasound and a lot more.
Invasive Therapeutic Procedures
While an invasive diagnostic procedure is used to confirm the presence of a disease, an invasive therapeutic procedure is used to treat a medical condition.
Surgeries are performed in order to correct anomalies, such as repair of fractures; or to remove damaged organ (appendectomy, hysterectomy, etc.), foreign bodies like bullets, or malignant tissues as with cancer cases.
As they involve cutting into the skin to reach the problematic body organs, all types of corrective surgeries therefore - either major or minor - are considered invasive therapeutic procedures.