Leukocytes – An overview of the different types and their importance

Different types of leukocytes

A blood test often analyzes both the total number of leukocytes and how the different types are distributed, known as the leukocyte differential. In this article, we will review the most common types of leukocytes and explain what they do in the body and what changed values ​​can mean.

Neutrophils – first on the scene in bacterial infections

Elevated neutrophils can be seen in:

• Bacterial infections
• Acute or chronic inflammation
• Physical or mental stress
• Cortisone treatment

Low neutrophils can be seen in:

• Viral infections
• Vitamin deficiency, especially B12 or folate deficiency
• Certain medications or bone marrow effects

Eosinophils – often linked to allergy and hypersensitivity

Eosinophilic granulocytes are a type of leukocyte that plays a particularly important role in allergic reactions and immunological hypersensitivity. They are normally present in low amounts in the blood, but can increase significantly when the immune system reacts to allergens or parasites. Eosinophils are involved in inflammatory processes in the respiratory tract, skin and gastrointestinal tract, among other things. Elevated levels are therefore often seen in conditions such as allergy, asthma and eczema, but can also occur in parasitic infections or certain drug reactions.

Elevated eosinophils can be seen in:

• Allergies (pollen, fur animals, foods)
• Asthma or eczema
• Parasitic diseases
• Certain drug reactions

Basophils – part of the body's allergic response

Basophil granulocytes are the least common type of leukocyte, but despite their low proportion, they play an important role in the body's immune defense. Basophils are particularly involved in allergic and inflammatory reactions and contribute, among other things, by releasing histamine and other signaling substances that affect blood vessels and inflammatory processes.

Basophils interact with other immune cells and are activated primarily in allergic conditions, but can also reflect ongoing low-grade inflammation in the body. Changes in basophil levels are therefore usually interpreted in relation to other leukocytes and clinical symptoms.

Elevated basophils can be seen in:

• Allergic conditions
• Chronic inflammation
• In rare cases, certain blood diseases

Lymphocytes – the specialized defense of the immune system

Lymphocytes are central to the body's long-term and specific immune defense. They are particularly important in viral infections and in building up an immunological memory.

Elevated lymphocytes can be seen in:

• Viral infections
• Recovery after infection
• Certain long-term infections

Low lymphocytes can be seen in:

• Stress and high cortisol exposure
• Cortisone treatment
• Impaired immune function

Monocytes – the body's cleaning and repair system

Monocytes are a type of leukocyte that plays an important role in long-term inflammation and the body's recovery processes. They circulate in the blood but can also migrate into the body's tissues, where they transform into macrophages that break down damaged cells, microorganisms and other cellular material.

Monocytes are particularly active when the body is in a healing phase after infection or inflammation. Elevated levels can therefore sometimes reflect that the immune system is working to clean up and repair after a previous stress.

Elevated monocytes can be seen in:

• Chronic or long-term inflammation
• Infections in the healing phase
• Autoimmune condition

What do leukocytes say about your well-being?

Leukocytes provide an overall picture of how the immune system works and how the body reacts to infection, inflammation and other stresses. For a correct assessment, it is important to interpret the values ​​in their context. Each type of leukocyte has its own function in the immune system. Through blood tests, both the total level and distribution can be analyzed, and all leukocyte markers can be ordered as a private referral from us at Testmottagningen.