U.S. Department of Health and Human Services

Diagnostic Tests A-Z

Select a letter to locate a diagnostic test.

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) conducts, supports, and coordinates research on many of the most serious diseases affecting public health. The NIDDK cannot provide medical advice for individuals. The information provided here is informed by NIDDK research, reviewed by doctors, and provided to help you understand more about the diseases and conditions you or your loved ones may face. The NIDDK is part of the National Institutes of Health, the medical research agency of the United States.​

A B C D E F 
G
 H I 
J
 K L M 
N
 O 
P
 
Q
 R S T U V 
W
 
X
 
Y
 
Z
 

A


African Americans, Hemoglobin Variants, Sickle Cell Trait, and the A1C Test


See
 For People of African, Mediterranean, or Southeast Asian Heritage: Important Information about Diabetes Blood Tests

Asian Americans, Hemoglobin Variants, Sickle Cell Trait, and the A1C Test


See
 For People of African, Mediterranean, or Southeast Asian Heritage: Important Information about Diabetes Blood Tests

B

Barium Enema


See
 Lower GI Series

Barium Swallow


See
 Upper GI Series

C

Colonoscopy

Colonoscopy is a procedure that uses a long, flexible, narrow tube with a light and tiny camera on one end to look inside your rectum and entire colon. Colonoscopy can show irritated and swollen tissue, ulcers, and polyps.

Comparing Tests for Diabetes and Prediabetes

Provides a concise summary for health care providers of blood tests for diabetes and prediabetes, covering uses, technical features, and pros and cons of different tests.

Cystoscopy and Ureteroscopy

Outlines possible reasons for cystoscopy and ureteroscopy and explains the preparation involved. Describes the procedures in detail, as well as what patients can expect afterward.

D

Diagnostic Testing for Diabetes and Prediabetes (for Health Care Professionals)


See
 Comparing Tests for Diabetes and Prediabetes

E

ERCP (Endoscopic Retrograde Cholangiopancreatography)

Describes the purpose of ERCP (endoscopic retrograde cholangiopancreatography, how patients can prepare for it, and what patients can expect during and after the procedure.

F

Fasting Plasma Glucose (FPG)


See
 Comparing Tests for Diabetes and Prediabetes

Flexible Sigmoidoscopy

Provides general information about flexible sigmoidoscopy. Describes the purpose of the test, how patients can prepare for it, and what patients can expect during and after the procedure. This publication is also available in Spanish.

For People of African, Mediterranean, or Southeast Asian Heritage: Important Information about Diabetes Blood Tests

Describes hemoglobin variants how they can cause false results for the A1C test. Discusses how false results can affect diabetes diagnosis and care in people with hemoglobin variants.


H



I

Imaging of the Urinary Tract

Explains the range of imaging technologies used to evaluate the urinary tract, including ultrasound, conventional radiology, magnetic resonance imaging, and computerized tomography.

Imaging Studies, Urologic Diseases


See
 Imaging of the Urinary Tract

K

Kidney Biopsy

Describes kidney biopsy and possible reasons for performing this diagnostic test. Outlines the preparations for and explains what patients can expect during and after the test.

L


Liver Biopsy

Provides general information about liver biopsy. Describes the purpose of the test, how patients can prepare for it, and what patients can expect during and after the procedure.

Lower GI Series

Provides general information about the lower gastrointestinal (GI) x-ray series. Describes the purpose of the test and what patients can expect before, during, and after the procedure. This publication is also available in Spanish.

M

Medical Tests for Prostate Problems

Reviews different prostate problems and lists key points to discuss with a doctor or nurse. Explains commonly performed tests, including a digital rectal exam and a prostate-specific antigen blood test.

O


Oral Glucose Tolerance Test (OGTT)


See
 Comparing Tests for Diabetes and Prediabetes

R


S

Sickle Cell Trait and Other Hemoglobinopathies and Diabetes: Important Information for Providers

Explains how the A1C test can lead to misdiagnosis, overtreatment, or undertreatment of diabetes in people with hemoglobinopathies. Explains when to suspect a patient has a variant.



T

Testing for Celiac Disease (For Healthcare Providers)

Describes tests that identify serological and genetic markers associated with celiac disease. If tests indicate the possibility of celiac disease, a biopsy determines diagnosis.



The A1C Test and Diabetes

Defines and explains the A1C diabetes blood test. Discusses using the test for diagnosis of diabetes and prediabetes and monitoring of glucose levels in people with type 1 or type 2 diabetes.

Thyroid Tests

Describes the different tests used to evaluate thyroid function and diagnose thyroid disease. Includes typical thyroid test results seen in thyroid diseases.

U

Upper GI Endoscopy

Upper gastrointestinal (GI) endoscopy is a procedure in which a doctor uses an instrument called an endoscope to see the lining of your upper GI tract. Doctors use upper GI endoscopy to find, and sometimes treat, problems in the upper GI tract.

Upper GI Series

Provides general information about upper gastrointestinal (GI) x-ray series. Describes the purpose of the test and what patients can expect before, during, and after the procedure. This publication is also available in Spanish.



Urodynamic Testing

Describes normal bladder function, as well as problems in the urinary system that may require urodynamic testing. Discusses different urodynamic procedures and why they are used.

V

Virtual Colonoscopy

Provides information about virtual colonoscopy. Describes the purpose of the test, how patients can prepare for it, and what patients can expect during and after the procedure.