Question

ESR (erythrocyte sedimentation rate) is meant for knowing
A. Degree of disease.
B. Erythrocyte count.
C. Plasma volume.
D. Percentage of hemoglobin.

Answer 1

Hint: ESR is a pathological test which is done for detection of the presence of inflammation caused by some diseases like infections, tumors or autoimmune diseases. It is also used for the diagnosis of some specific conditions such as temporal arteritis, systemic vasculitis, polymyalgia rheumatoid, or rheumatoid arthritis.

Complete answer:
ESR or erythrocyte sedimentation rate is a test in which we measure the rate at which erythrocyte or red blood cells fall (sediments) when a blood sample has been placed into a tall, thin, vertical tube. Erythrocyte sedimentation rate is a test that indirectly measures the degree of inflammation in the body. When RBC falls down or sediments after one hour, we get a clear fluid (plasma) which is present at the top of the tube.

When a healthy blood sample is placed in a tube, the RBC settles out slowly, leaving little clear plasma. But, the rate of sedimentation increases in case of inflammation. The ESR is not a diagnostic test, it is a non-specific test that may have elevated other conditions. So, we say erythrocyte sedimentation rate is meant for knowing the degree of inflammation or degree of disease. We have four options: Degree of disease, Erythrocyte count, Plasma volume and percentage of hemoglobin.

Hence, the correct answer is option (A).

Note: In inflammation, some proteins called acute phase proteins increase and erythrocytes or RBC settles faster in presence of these acute phase proteins. Some examples of acute phase proteins are: C-reactive protein and fibrinogen. They may also increase in other conditions, that's why ESR is a non-specific test.