be beside yourself. C2 If you are beside yourself with a particular feeling or emotion, it is so strong that it makes you almost out of control: He was beside himself with grief when she died. (Definition of âbe beside yourselfâ from the Cambridge Advanced Learnerâs Dictionary & Thesaurus Â© Cambridge University Press)
Rheumatoid Factor Test. The rheumatoid factor is an antibody present in the blood of many patients with rheumatoid arthritis. Doctors measure the level of rheumatoid factor by performing a blood test. A positive rheumatoid factor test means that the patientâs level of rheumatoid factor in their blood is considered high.
1 In other words, if the Rhesus antigen is present in your red blood cells, you're Rh positive (which means you have a positive blood type). 2  But if the Rh antigen is absent from your red blood cells, you're Rh negative (which means you have a negative blood type). The Rhesus antigen is a particular protein only found in the red blood cells of people with positive blood types. 2  In other words, if the Rhesus antigen is present in your red blood cells, you're Rh positive (which means you have a positive blood type).