Rheumatoid factor (RF) is a blood test that measures the amount
of the RF antibody in the blood. A blood sample is needed. For
information on how this is done, see: Venipuncture No special
preparation is usually necessary. When the needle is inserted to
draw blood, some people feel moderate pain, while others feel
only a prick or stinging sensation. Afterward, there may be some
throbbing. Goodyear CS, Tighe H, McInnes IB. Rheumatoid factors
and other autoantibodies in rheumatoid arthritis. In: Firestein
GS, Budd RC, Harris Jr. ED, McInnes IB, Ruddy S, eds. Kelley's
Textbook of Rheumatology. 8th ed. Philadelphia, Pa: W.B.
Saunders Company;2008:chap 51. © 2011 University of Maryland
Medical Center (UMMC). All rights reserved. UMMC is a member of
the University of Maryland Medical System, 22 S. Greene Street,
Baltimore, MD 21201. TDD: 1-800-735-2258 or 1.866.408.6885