Methods in Medical Diagnostics

Diagnosis is the identification of the nature and cause of disease. Diagnosing diseases and conditions is done by observing the signs, symptoms and test results of a particular health problem or set of problems. Some diagnostic tests are invasive, while others require very little sacrifice on the part of the patient. The most common diagnostic methods include direct examination, exploratory surgery, blood analysis, body fluid and tissue testing and radiology.

Direct Examination

• Palpation is one method of direct examination.

  One of the easiest and most inexpensive methods for diagnosing illness is by direct examination. Basically, a medical practitioner observes a patient, or a particular part of a patient, and makes a determination based on what he sees. This method is particularly useful for medical problems that affect the surface of the body, like fungal infections, cellulitis and contact allergic reactions. If a diagnosis is not made, often these external signs may be clues to what the underlying condition may be.

  Exploratory surgery is also another method of examination, though it requires the patient to go under anesthesia and have a part of their body cut open in most cases.

  A thorough medical history will also help the doctor make an appropriate diagnosis, and may be used in conjunction with any of the methods listed here.

Body Fluid and Tissue Testing

• Your blood contains many components.

  Rather invasive but far more definitive than direct examination is body fluid or tissue testing. Human blood contains many components that all play an important part in maintaining homeostasis. By extracting some of a patient's blood and examining it under a microscope or in a computer, abnormalities can be easily identified. For instance, too many white blood cells can indicate leukemia, while too little hemoglobin can indicate an anemic condition. Also, the presence of infection, parasites or viruses can be found. Blood testing is often the first step in many diagnostic paths.

  Other body fluids and tissues can also be examined for health or illness, such as urine, feces, vaginal fluids, semen, spinal fluid, saliva and sputum.

  Tissues can be excised from anywhere in the body (called a Biopsy) and more easily examined for abnormalities, such as cancer.

Radiology

• Magnetic resonance imaging is one method of radiology.

  Radiology is the process of taking a photograph of the inside of the body. This is done with several different machines that take different types of images, such as X-Rays, CT scans (computed tomography), MRI (magnetic resonance imaging) and ultrasound.

  None of these methods is particularly invasive, but some may require some sacrifice on the part of the patient. The MRI, for instance, uses magnets to take detailed pictures of a part of the body, but many have fears about this test because it produces loud noises and often means the patient is confined to an enclosed space for an extended period of time. Some of these tests, like X-Ray and CT, also expose the body to radiation, which raises some concerns if the patient is pregnant or has to have the tests repeated many times in their life. These test are also very expensive. An MRI can cost over a $1,000 in some cases.

Diagnosis By Treatment

• Sometimes, treatment is started before diagnosis is confirmed.

  Occasionally, diseases, illnesses and conditions are treated before they are formally diagnosed. If the physician does not know exactly what the problem is, sometimes an assumption is made and a treatment is attempted to see if the problem changes or responds. If it does, chances are excellent that the doctor was correct in his assumption. If there is no response, then the doctor can usually rule out the problem he suspected.

  This method is only used if the treatment is mild and using it causes little or no harm, or in the event that the patient is facing an illness where no treatment, or delayed treatment would cause more harm than taking the time to properly diagnose the patient's problem.