18 Hidden Causes of High Neutrophil Counts That Doctors Want You to Know

17. Pregnancy

Pregnancy is associated with natural changes in the immune system, including mild neutrophilia. During pregnancy, the body undergoes hormonal shifts that alter blood composition, including an increase in white blood cell production. Neutrophils rise gradually throughout pregnancy, particularly in the third trimester, as the body prepares for labor and delivery. This increase is considered a normal physiological adaptation and does not indicate an infection or underlying disease unless accompanied by other symptoms. However, in some cases, gestational neutrophilia can be more pronounced if there are additional factors at play, such as an infection, stress, or pre-existing inflammatory conditions. Postpartum, neutrophil levels typically return to normal within a few weeks. While pregnancy-related neutrophilia is not a cause for concern in most cases, monitoring blood counts during prenatal visits helps ensure maternal and fetal well-being.

18. Allergic Reactions and Anaphylaxis

While allergies are typically associated with an increase in eosinophils (another type of white blood cell), severe allergic reactions can also trigger neutrophilia. During an allergic response, the immune system releases histamines and inflammatory cytokines, leading to increased production and mobilization of neutrophils. In cases of anaphylaxis, a life-threatening allergic reaction, neutrophils may be rapidly deployed to help counteract widespread inflammation and tissue damage. Additionally, chronic allergic conditions such as allergic asthma and hay fever can contribute to mild, persistent neutrophilia due to ongoing immune activation. Understanding how allergic responses influence white blood cell levels can help individuals manage their symptoms more effectively and seek appropriate treatment when necessary.