Radioallergosorbent test, an allergy test that is done on a sample of blood. RAST is used to check for allergic sensitivity to specific substances.
- Rat-flea typhus
Murine typhus, an acute infectious disease with fever, headache, and rash, all quite similar to, but milder than, epidemic typhus, caused by a related microorganism, Rickettsia typhi (mooseri), transmitted to humans by rat fleas (Xenopsylla cheopis). The animal reservoir includes rats, mice and other rodents. Murine typhus occurs sporadically worldwide but is more prevalent in […]
- Rate, basal metabolic
A measure of the rate of metabolism. For example, someone with an overly active thyroid will have an elevated basal metabolic rate.
- Rate, birth
The birth rate is usually given as the number of live births divided by the average population (or the population at midyear). This is termed the crude birth rate. In 1995, for example, the crude birth rate per 1,000 population was 14 in the United States, 16.9 in Australia, etc.
- Rate, death
The number of deaths in the population divided by the average population (or the population at midyear) is the crude death rate. In 1994, for example, the crude death rate per 1,000 population was 8.8 in the United States, 7.1 in Australia, etc. A death rate can also be tabulated according to age or cause.
- Rate, erythrocyte sedimentation
A sedimentation rate, or “sed rate”, is a blood test that detects and is used to monitor inflammation activity. It is measured by recording the rate at which red blood cells (RBCs) sediment in a tube over time. It increases (the RBCs sediment faster) with more inflammation.