In recent years, Spanish researchers have been increasingly focused on how psychological issues affect the health of young women. A new study conducted in 2025 has revealed a troubling trend: girls suffering from anxiety and insomnia show a marked decrease in so-called natural killers—cells responsible for the body’s first line of defense against viruses and tumors. This finding may explain why chronic stress and sleep disorders so often lead to serious illnesses.
Scientists from Taibah University conducted a cross-sectional study with 60 female students aged 17 to 23. Each participant completed a detailed survey assessing their anxiety levels and sleep quality. Afterwards, blood samples were taken to determine the number and activity of NK cells—the immune system’s key defenders.
Immunity at risk
The results were quite telling. More than half of the participants reported regular sleep problems, while three-quarters admitted to elevated anxiety levels. Blood tests showed that those suffering from insomnia had significantly lower counts of the CD16+CD56 cell subpopulation compared to their calm and well-rested peers. This difference was most pronounced in girls with severe anxiety, whose NK cell levels and their subsets were at their lowest.
Statistical analysis has confirmed: the higher the anxiety, the lower the number of protective blood cells. This relationship persisted even after accounting for other factors such as age, lifestyle, and chronic illnesses. The correlation was so strong that researchers are calling for a reassessment of disease prevention strategies for young women.
Mental health and immunity
Natural killers are a special type of lymphocyte that are the first to respond to the appearance of viruses and abnormal cells. They normally make up 5 to 15 percent of all lymphocytes in the blood. When their numbers decrease, the body loses its ability to quickly detect and eliminate threats. That’s why a drop in NK cells can lead to cardiovascular and oncological diseases.
The authors of the study note that chronic stress and insomnia not only worsen overall well-being, but also trigger complex biochemical processes that affect the immune system. Inflammatory reactions caused by ongoing tension may result in serious disruptions in the body. Young women are especially vulnerable to these effects, as their psychological and hormonal systems are not yet fully stabilized.
New challenges for medicine
The findings have prompted experts to consider the importance of early diagnosis and treatment of anxiety disorders in young women. Early detection of mental health and sleep issues could prove crucial in preventing serious illnesses. Doctors emphasize: ignoring anxiety and insomnia means putting yourself at risk for weakened immunity and the development of chronic diseases.
Interestingly, even small changes in lifestyle—such as regular physical activity, meditation, or laughter therapy—can significantly boost NK cell levels. Other studies conducted in Spain and elsewhere confirm these results. However, specialists warn that self-treatment is not always effective, and at the first signs of anxiety, it’s best to consult a doctor.
Looking ahead
Despite the limited number of participants, the study has already generated significant interest in the scientific community. Experts believe the results could serve as a starting point for large-scale projects aimed at exploring how psycho-emotional factors affect immunity. In the coming years, similar studies will be conducted among different age and social groups to determine how universal these patterns are.
For now, scientists advise not to underestimate the importance of psychological comfort and proper sleep in maintaining good health. This is especially relevant for young women, who often face increased demands and stress in their studies, work, and personal lives. Taking care of yourself is not a luxury—it’s essential for a strong immune system and a long life.
In case you didn’t know, Taibah University is one of the leading research centers in medicine and psychology in the Middle East. In recent years, its specialists have actively collaborated with their European counterparts, including those from Spain, developing new methods for diagnosing and preventing psychosomatic disorders. Their work is regularly published in prestigious international journals and receives high marks from experts.
