Published: 28 Jan 2024

Understanding Test Results

The interpretation of a test result, determining whether it indicates illness, risk, or health status, relies heavily on your healthcare provider's assessment of all available information about your health. This includes your medical history, physical exam findings, current symptoms, medications, and other non-laboratory tests.

Reference Ranges

A reference range is a set of values that include upper and lower limits for a laboratory test. These ranges represent the expected variations or "normal limits" observed in a group of healthy individuals.

Although "reference range" is the preferred term used by healthcare professionals, "reference interval" is also commonly used, hence its usage in this article.

Reference ranges provide a basis for comparing your test results and determining your health status. These values may vary based on factors such as your age, sex, and the type of specimen being tested (e.g., blood, urine, spinal fluid). Circumstances such as fasting or exercise can also influence these ranges.

Interpreting Results

Some tests may not have specific reference ranges, but instead have established thresholds that indicate whether you are healthy or require treatment. These thresholds have often been standardized through extensive research involving large, diverse populations.

In the context of your personal health, reference ranges can serve as a guide for interpreting your results and making informed decisions about managing your health. An example of this is glucose testing for diabetes.

Laboratory-Specific Ranges

Each laboratory establishes its own reference ranges through a process called "validation." Therefore, these ranges can vary from lab to lab. The specific reference ranges reported on your lab results will be provided by the laboratory that performed the test.

Reference ranges provide insights into what is considered normal for a particular population, based on age, sex, and other relevant characteristics.