Health Explained
False-Positive and False-Negative Results Explained
No test is perfect: these terms describe results that do not match whether the condition is truly present.
Health Explained
Plain-English explainers for health terms, body systems, lab terms, and common medical concepts.
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Health Explained
Lab Reference Ranges: Why the Number Is Not a Diagnosis
A result outside a lab's reference range may need context, while an in-range result does not always rule out a problem.
Health Explained
Uric Acid Test Explained: Blood Levels, Urine, and Gout Context
A uric acid test may use blood or urine and can support evaluation of gout, kidney stones, or other conditions. A level alone cannot diagnose the cause of joint pain.
Health Explained
TSH Test Explained: What This Thyroid Blood Test Can Tell You
A TSH result offers a clue about thyroid signaling, but it may not explain the cause of an abnormal result by itself.
Health Explained
Triglycerides Explained: What a Blood Test Measures
Learn what triglycerides are, how they differ from cholesterol, and why a clinician interprets results alongside other health information.
Health Explained
Mammogram Explained: Screening, Diagnostic Imaging, and Follow-Up
How mammograms use X-rays to examine breast tissue, how screening differs from diagnostic imaging, and what to ask about results.
Health Explained
Lipase Test Explained: What a Pancreas Enzyme Result Can Mean
A blood lipase test can help evaluate pancreatic problems, including pancreatitis, but other conditions and medicines can affect results. The number must be interpreted with symptoms and other findings.
Health Explained
HDL Cholesterol Explained: What the Number Can and Cannot Tell You
HDL is often called good cholesterol, but a lab result is one part of a broader cardiovascular risk picture.
Health Explained
Fasting Blood Glucose Test Explained: Preparation and Results
A fasting plasma glucose test measures blood sugar at one point in time. The lab and clinician will explain whether fasting is needed and how a result fits with other tests.
Health Explained
EMG and Nerve Conduction Studies Explained: Signals, Needles, and Results
EMG and nerve conduction studies assess electrical activity in muscles and nerves; results are interpreted with symptoms and other tests.
Health Explained
eGFR Explained: What a Kidney Blood-Test Estimate Means
eGFR estimates how well the kidneys filter blood, but a clinician interprets it with urine tests, trends, and the person's medical context.
Health Explained
Echocardiogram Explained: What the Heart Ultrasound Can Show
How an echocardiogram uses sound waves, what common types assess, and what to ask about preparation and results.
Health Explained
Comprehensive Metabolic Panel (CMP) Explained: 14 Results, Many Contexts
A CMP measures glucose, electrolytes, proteins, and liver- and kidney-related markers; no single result diagnoses a condition by itself.
Health Explained
Complete Blood Count (CBC) Explained: Cells, Components, and Context
A CBC measures several blood cell features, but an out-of-range value is not a diagnosis by itself.
Health Explained
Colonoscopy Explained: Preparation, Procedure, and Results
What colonoscopy examines, why bowel preparation matters, what to expect during and after the procedure, and questions about results.
Health Explained
C-Peptide Test Explained: What It Can Show About Insulin Production
A C-peptide test can help clinicians estimate how much insulin the pancreas is making. Results are interpreted with glucose levels, medicines, symptoms, and the reason for testing.
Health Explained
ANA Test Explained: Why a Positive Result Is Not a Diagnosis
An ANA test looks for antinuclear antibodies and can help evaluate autoimmune disease, but healthy people can also test positive. Clinicians interpret the result alongside symptoms and other findings.
Health Explained
A1C Test Explained: What the Result Can and Cannot Tell You
The A1C test estimates average blood glucose over roughly three months, but conditions such as anemia and pregnancy can affect accuracy.
Health Explained
Lung Function Tests Explained: Spirometry, Preparation, and Results
Pulmonary function tests measure aspects of breathing, and spirometry checks how much and how quickly you can blow air out. Results are interpreted against personal factors and symptoms.
Health Explained
Blood Typing Explained: ABO Groups, Rh Factor, and Compatibility
Blood typing identifies ABO group and Rh status, information used in transfusion care and some pregnancy-related testing. Knowing your type does not make every transfusion compatible.