From the Guidelines
Diagnosing a medical condition requires a systematic approach that includes a thorough medical history, physical examination, and diagnostic tests to confirm or rule out suspected conditions. This process involves collecting information about symptoms, their duration, severity, and any factors that worsen or improve them, as well as considering family history, lifestyle factors, and previous medical conditions 1. Physical examinations help identify abnormal findings that may indicate specific diseases. Diagnostic tests, such as blood tests, imaging studies (X-rays, CT scans, MRIs), biopsies, and specialized tests like electrocardiograms or pulmonary function tests, provide objective data to support or refute a diagnosis.
Key Steps in Diagnosis
- Collecting a thorough medical history
- Performing a physical examination
- Ordering diagnostic tests as needed
- Interpreting test results in the context of the patient's situation
- Considering multiple possible diagnoses and ruling out alternatives
In some cases, monitoring symptoms over time or response to treatment may be part of the diagnostic process, especially when the diagnosis is not immediately clear or when chronic conditions are suspected 1. The healthcare provider must integrate all the information—symptoms, physical findings, test results, and clinical judgment—to arrive at a diagnosis. This process requires medical training and expertise, as many conditions share similar symptoms, and test results must be interpreted carefully. Patients should always seek professional medical evaluation rather than attempting self-diagnosis, as this ensures the most accurate and effective diagnosis and treatment plan.
Importance of Professional Evaluation
- Ensures accurate diagnosis
- Allows for appropriate treatment planning
- Prevents misdiagnosis or delayed diagnosis
- Provides patients with the best possible outcomes in terms of morbidity, mortality, and quality of life.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Diagnostic Process
To diagnose a medical condition, healthcare professionals use a combination of tools and techniques, including:
- Medical interview: gathering relevant patient characteristics to fit a particular condition 2
- Physical examination: supporting the categorization of the patient's condition 2
- Complementary tests: such as complete blood cell count (CBC), chemistry panel, urinalysis, and imaging tests like CT-scan or X-ray 3, 4, 5
Diagnostic Tests
Diagnostic tests are used to estimate the probability of the presence or absence of a suspected medical condition. The usefulness of these tests varies for each clinical condition, and their accuracy is evaluated through studies of sensitivity, specificity, and diagnostic impact 2, 6. Examples of diagnostic tests include:
- Complete blood cell count (CBC): a powerful diagnostic tool that can lead to a specific diagnosis or assist in ruling out many diseases when used in conjunction with a good history and physical examination 3
- CT-scan: a confirmation test that can outperform chest X-ray in diagnosing pneumonia, but its use should be guided by a simple prediction score to avoid unnecessary scans 4
Clinical Utility
The clinical utility of diagnostic tests expresses the extent to which diagnostic testing improves health outcomes relative to the current best alternative. This can be estimated through comparative randomized clinical trials, and it is essential to link diagnostic accuracy to clinical utility through an appropriate definition of the target condition in diagnostic-accuracy studies 6.
Imaging Features
Imaging features, such as radiographic and CT patterns, can aid in differentiating viral pathogens and reducing the use of antibiotics. Recognition of viral pneumonia patterns can help radiologists suggest the diagnosis of viral pneumonia, considering both clinical and radiologic characteristics 5