The Terminology- SNOMED CTÂ®, an Evolving Clinical Reference Terminology. SNOMEDÂ® is the Systemized Nomenclature of Medicine. It is a controlled medical terminology (CMT). At its simplest, a SNOMED is a coded vocabulary of medical concepts and expressions used in healthcare.
The partial thromboplastin time (PTT) is a screening test that helps evaluate a person's ability to appropriately form blood clots. It measures the number of seconds it takes for a clot to form in a person's sample of blood after substances (reagents) are added.
To test your bodyâs blood clotting abilities, your doctor will collect a sample of your blood in a vial and add chemicals. The test measures how many seconds it takes for your blood to clot after the addition of the chemicals. This test is sometimes known as an activated partial thromboplastin time (APTT) test. Your doctor may order a PTT test to investigate the cause of prolonged or excessive bleeding. Symptoms that may prompt your doctor to order this test include: 1  frequent or heavy nosebleeds.  heavy or prolonged menstrual periods.