Peripheral blood smear

Clinical definition of the Peripheral blood smear test
A peripheral blood smear is a thin layer of blood smeared on a microscope slide and stained which allows blood cells to be examined microscopically. A blood smear allows the evaluation of white blood cells (WBCs, leukocytes), red blood cells (RBCs, erythrocytes) and platelets (thrombocytes). Blood smear is examined to investigate hematological problems (disorders of the blood) and, occasionally, to look for parasites within the blood such as malaria and filaria.

Why is the Peripheral blood smear test done?
A blood smear is a blood test that gives information about the number and shape of blood cells. Peripheral blood smear test is carried out:

  • As part of a general health exam to help diagnose many illnesses
  • To determine if red blood cells, white blood cells and platelets are normal in appearance and number
  • To distinguish between different types of white blood cells
  • To determine their relative percentages in the blood
  • To help diagnose a range of deficiencies, diseases and during chemo/radiation therapy
  • In the evaluation for hemoglobin variants
  • Determines presence of Malaria / Filaria

What are the common signs/symptoms when the Peripheral blood smear test is done?

  • A general feeling of tiredness or weakness
  • Lack of energy
  • Frequent infections
  • Fatigue
  • Bone and joint pain
  • Excessive bleeding and bruising
  • Fever
  • Weakness
  • Fatigue
  • Weight loss
  • Swollen lymph nodes, liver, spleen, kidneys, and testicles
  • Frequent infections
  • Headaches
  • Vomiting
  • Confusion
  • Seizures (may occur when cells are increased in the brain or central nervous system)
  • Night sweat

What should I do before the Peripheral blood smear test?

Specimen type

Specimen collection procedure

Preparatory instructions before the test *


(Blood Sample)


(Collection of blood from a vein, usually from the arm)

No Fasting Required.

No other special preparations required.

*Subjects suffering from any illness or on oral or injectable medications are advised to consult their physician prior to requesting any tests or procedures.

How do I interpret my Peripheral blood smear test results?
Peripheral blood smear test results cover Hb RBC, WBC, Differential count and parasites if any.

Reference Range*



See Individual test


See Individual test


See Individual test

Differential count

See Individual test


7.35- 7.45



‘*A Reference range is a set of values which helps the healthcare professional to interpret a medical test. It may vary with age, gender, and other factors. Reference ranges may also vary between labs, in value & units depending on instruments used and method of establishment of reference ranges’

Diseases/conditions related to the Peripheral blood smear test

  • Leukemia
  • Anemia
  • Allergies
  • Parasitic infections
  • Chicken pox
  • Ulcerative Colitis
  • Cancer
  • Hairy cell leukemia
  • Hemoglobinopathies

Other tests related to the Peripheral blood smear test

  • CBC
  • Differential
  • RBC
  • WBC
  • Platelet Count
  • Reticulocyte count
  • Hemoglobin variants

Synonyms : Red blood cell morphology