Blood test

Normal eosinophil count in the blood

Blood test
Normal eosinophil count in the blood
Last update: 04/03/2021

What is the normal count of eosinophils in the blood?

The normal count of eosinophils in the blood is age-dependent:

Adults: 50 - 500 /µl (microliter)
Children from 12 to 18 years old: 30 - 400 /µl (microliter)
Children from 3 to 12 years old: 20 - 500 /µl (microliter)
Children from 2 to 3 years old: 30 - 525 /µl (microliter)
Children from 6 months old to 2 years old: 20 - 825 /µl (microliter)
Babies from 2 to 6 months old: 20 - 750 /µl (microliter)
Babies from 4 weeks old to 2 months old: 40 - 625 /µl (microliter)
Babies from 2 to 4 weeks old: 60 - 800 /µl (microliter)
Newborns up to 2 weeks old: 100 - 650 /µl (microliter)

Why normal levels can differ across different labs?

Each laboratory must establish its own normal ranges for the eosinophil count in the blood. These ranges depend on the makeup of the local population, the technologies used and the accuracy of the measurement. There may be also slight differences in the normal levels, according to age, gender, race or ethnic origin, geographic region, diet, type of sample and other relevant status.

Your doctor will study the results along with your medical record, screenings, physical condition, symptoms and any other relevant information about your situation.

The normal eosinophil count is lowest in the morning and then rises with peak levels recorded around midnight. For this reason, serial eosinophil counts should be repeated at the same time each day.

What is the role of eosinophils in the body?

Eosinophils are a type of WBCs (White Blood Cell) that play an important role in the immune system.

Eosinophils play two primary functions in the immune system:

  • Protect the body against parasites worms.
  • Respond to allergic reactions and become active in the later stages of inflammation.

Eosinophils are present in the bloodstream but they can also be found in the lower gastrointestinal tract, thymus, spleen, lymph nodes, ovaries and uterus.

If there is a high presence of eosinophils in the skin, lungs or esophagus, it suggests a possible disease.

What is the eosinophil count used for?

Eosinophils are present in the bloodstream as a transition from their production in the bone marrow to their migration to the tissues where they play an important role.

Eosinophils remains in the bloodstream just a few hours (18 hours average) before they move into the tissues.

This test is used to diagnose allergic infections, assess severity of infestations with worms and other large parasites, and monitor response to treatment.

A high count of eosinophils in the blood is called eosinophilia and may be due to:

  • Allergic diseases (asthma, allergic rhinitis)
  • Skin diseases
  • Parasitic infections
  • Leukemia (blood cancer)
  • Medication

There are several diseases related to eosinophilia where the eosinophil count may help to get a diagnosis.

A chronic eosinophilia may cause tissue damage.

A low eosinophil count in the blood is rare. It is called eosinopenia and it is not usually a matter for concern. The main reasons for a low eosinophil count for a long time is medication (corticosteroids). Eosinopenia has also been reported in case of Cushing's syndrome and typhoid fever.

Where can I find more information about eosinophil count in the blood?

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Which values are considered a normal eosinophil count in the blood?

The following values are considered to be normal values:

IMPORTANT: These levels are expressed in number /µl (microliter). They are an example of a healthy white man/woman of about 45 years old with no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.

50 /µl52 /µl54 /µl56 /µl58 /µl60 /µl62 /µl64 /µl
66 /µl68 /µl70 /µl72 /µl74 /µl76 /µl78 /µl80 /µl
82 /µl84 /µl86 /µl88 /µl90 /µl92 /µl94 /µl96 /µl
98 /µl100 /µl102 /µl104 /µl106 /µl108 /µl110 /µl112 /µl
114 /µl116 /µl118 /µl120 /µl122 /µl124 /µl126 /µl128 /µl
130 /µl132 /µl134 /µl136 /µl138 /µl140 /µl142 /µl144 /µl
146 /µl148 /µl150 /µl152 /µl154 /µl156 /µl158 /µl160 /µl
162 /µl164 /µl166 /µl168 /µl170 /µl172 /µl174 /µl176 /µl
178 /µl180 /µl182 /µl184 /µl186 /µl188 /µl190 /µl192 /µl
194 /µl196 /µl198 /µl200 /µl202 /µl204 /µl206 /µl208 /µl
210 /µl212 /µl214 /µl216 /µl218 /µl220 /µl222 /µl224 /µl
226 /µl228 /µl230 /µl232 /µl234 /µl236 /µl238 /µl240 /µl
242 /µl244 /µl246 /µl248 /µl250 /µl252 /µl254 /µl256 /µl
258 /µl260 /µl262 /µl264 /µl266 /µl268 /µl270 /µl272 /µl
274 /µl276 /µl278 /µl280 /µl282 /µl284 /µl286 /µl288 /µl
290 /µl292 /µl294 /µl296 /µl298 /µl300 /µl302 /µl304 /µl
306 /µl308 /µl310 /µl312 /µl314 /µl316 /µl318 /µl320 /µl
322 /µl324 /µl326 /µl328 /µl330 /µl332 /µl334 /µl336 /µl
338 /µl340 /µl342 /µl344 /µl346 /µl348 /µl350 /µl352 /µl
354 /µl356 /µl358 /µl360 /µl362 /µl364 /µl366 /µl368 /µl
370 /µl372 /µl374 /µl376 /µl378 /µl380 /µl382 /µl384 /µl
386 /µl388 /µl390 /µl392 /µl394 /µl396 /µl398 /µl400 /µl
402 /µl404 /µl406 /µl408 /µl410 /µl412 /µl414 /µl416 /µl
418 /µl420 /µl422 /µl424 /µl426 /µl428 /µl430 /µl432 /µl
434 /µl436 /µl438 /µl440 /µl442 /µl444 /µl446 /µl448 /µl
450 /µl452 /µl454 /µl456 /µl458 /µl460 /µl462 /µl464 /µl
466 /µl468 /µl470 /µl472 /µl474 /µl476 /µl478 /µl480 /µl
482 /µl484 /µl486 /µl488 /µl490 /µl492 /µl494 /µl496 /µl
498 /µl500 /µl      
Medically reviewed by our Medical staff on 04/03/2021


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  • A Manual of Laboratory and Diagnostic Test. 9th edition. Frances Fischbach. Marshall B. Dunning III. 2014. Pag 75. ISBN-10: 1451190891.
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  • Common Terminology Criteria for Adverse Events (CTCAE). Version 5.0.Published: November 27, 2017. U.S. Department of health and human Services. Available on:

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