A study done over the passage of time. For example, a longitudinal study of children with Down syndrome (trisomy 21) might involve the study of 100 children with this condition from birth to 10 years of age. Also called a diachronic study. The opposite of a cross-sectional (synchronic) study.
- Study, preclinical
A study to test a drug, procedure or medical treatment in animals. The aim is to collect data in support of safety. Preclinical studies are required before clinical trials can be started.
- Study, stomach emptying
Also called a gastric emptying study, this test evaluates the emptying of food from the stomach. For a gastric emptying study, a patient eats a meal in which the solid food, liquid food or both are mixed with a small amount of radioactive material. A scanner (acting like a Geiger counter) is placed over the […]
- Stuffy nose
The presence of increased secretions and mucus in the nasal passages, most commonly arising as a result of a common cold, allergic reaction, or inflammation or infection of the paranasal sinuses (sinus infection).
- Sturge-Weber syndrome
A congenital, but not inherited, disorder that affects the skin, the neurological system, and sometimes the eyes. The main sign of Sturge-Weber syndrome is a port wine stain birthmark. Neurological symptoms may include seizures and developmental delay. Also known as encephalotrigeminal angiomatosis. See also port wine stain.
A red, tender bump on the eyelid that is caused by an acute infection of the oil glands of the eyelid. The medical term for a stye is hordeolum.