<s>[INST] context: Factors affecting ESR
1. Plasma

RBCs carry a negative electric charge, whereas plasma carries a postive charge.
Any condition in plasma that increases its positive charge, increases the rouleaux formation and increases ESR by lengthening stage I.
Following factors increase positive charge and ESR : -

i) Fibrinogen → Any condition which increases fibrinogen level will increase ESR - e.g.,
a) Infection
b) Inflammation
c) TB
ii)  Globulin → Conditions which increases globulin level will increase ESR.

Kala azar
Multiple myeloma
Some lymphoproliferative disorders
Rheumatic fever

iii) Cholesterol → Hypercholesterolemia increases ESR.

Any condition in plasma that decreases its positive charge, decreases rouleaux formation and decreases ESR.
	(a) Albumin → Hyperalbuminemia decreases ESR.
	(b) Decreased fibrinogen → In afibrinogenemia, ESR is zero.

2. RBC's - Increase in blood count as in polycythemia decreases ESR due to the jostling (or pushing one another) effect on the cells.
- Anemia increases the ESR by opposite effect, there are two exceptions.
i) Sickle cell anemia
ii) Microcytic hypochromic anemia (iron deficiency, Thalassemia)
In the last two types of anemia, ESR decreases because altered red cell shape prevents rouleux formation.

3. Physiological variations
ESR is low in infancy
ESR is high at puberty
ESR is greater in women than man.

4.Ohters
ESR is decreased in congestive heart failure
ESR is increased in acute myocardial infarction [/INST] question: ESR is increased in - | options: A: Sickle cell anemia B: Multiple myeloma C: Polycythemia vera D: Thalassemia | answer: B </s>