Complete Blood Count (CBC) Test
This test counts basophils (a type of white blood cell) in your sputum (mucus from your lungs) to help doctors check for respiratory conditions.
{"Basophils are white blood cells that help your body fight infections and respond to allergies","This test uses a microscope to manually count basophils in a sputum sample","It helps doctors diagnose infections, inflammation, or allergic conditions in your airways","You will need to cough up sputum from your lungs for the sample","Results help your doctor understand what's causing your respiratory symptoms"}
Key facts at a glance
- LOINC
- 21094-8
- Short code
- BASP
- Synonyms
- Basophils NFr Spt Manual
- Category
- chemistry
- Sample
- sputum
- Container
- Sterile, wide-mouth, leak-proof sputum collection container
- Units
- N/A
- Ref low
- 0
- Ref high
- 0
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- manual-count
- CPT
- 89190
- SNOMED
- 734480008
- Specimen volume
- 1-5 mL
- Stability
- Refrigerated (2-8°C): up to 2 hours; Room temperature: up to 1 hour for optimal cell preservation
- TAT
- 2–24 hours
- Order
- routine
What is a complete blood count (CBC)?
The sputum basophil test is a laboratory test that counts the number of basophils in a sample of your sputum. Basophils are a type of white blood cell (leukocyte) that play an important role in your immune system. They help protect your body by releasing chemicals like histamine during allergic reactions and fighting off parasites.
Why might my doctor order a complete blood count (CBC)?
Your doctor may order this test if you have symptoms of a respiratory condition, such as persistent cough, wheezing, shortness of breath, or excessive mucus production. The test helps determine if your symptoms are caused by an infection, inflammation, allergic reaction, or other condition affecting your airways and lungs.
How is the blood sample for a CBC collected?
You will need to provide a sputum sample, which is the mucus that comes from your lungs when you cough deeply. You may be asked to rinse your mouth first to avoid contamination with saliva. You will then cough forcefully to bring up sputum from your lungs into a sterile container. The sample is sent to a laboratory where a technician examines it under a microscope to count the basophils manually.
What do my CBC test results mean?
Results are typically reported as a percentage or ratio of basophils to total white blood cells in the sample. Elevated basophil levels may indicate an allergic reaction, parasitic infection, or inflammatory condition. Low levels are less common but may occur in certain infections or as a reaction to medications. Your doctor will interpret your results based on your symptoms and other test findings.
Are there any risks with a complete blood count (CBC)?
This test is very safe with minimal risks. You may feel some discomfort when coughing deeply to produce the sample. In rare cases, coughing may cause minor throat irritation or shortness of breath, especially in people with existing lung conditions.
Reference range
Few or none; basophils are typically not present in normal sputumN/A
Rinse mouth with water prior to collection. Avoid food, drink, or smoking for at least 1 hour before specimen collection. Deep cough specimen preferred, preferably collected in the early morning.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
The sputum basophil count helps doctors diagnose and monitor conditions affecting the respiratory tract. Elevated basophils may indicate allergic asthma, allergic bronchopulmonary aspergillosis, parasitic lung infections, or chronic inflammation. The test is often used alongside other tests (like complete blood count, sputum culture, or chest X-ray) to get a complete picture of your respiratory health. It can also help distinguish between different types of respiratory conditions that may present with similar symptoms.
Frequently asked questions
Do I need to fast before this test?
How long does it take to get results?
What happens if my basophil count is high?
Can I do this test at home?
Is this test painful?
Sources
- 1
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- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy