6. Immune System Suppression
Spaceflight exposes astronauts to conditions that can suppress immune system function. Microgravity alters the activity of white blood cells, which are essential for fighting off infections. Combined with the stress of space travel, these changes can leave astronauts more vulnerable to common and opportunistic infections, making even minor illnesses a significant concern during missions. Researchers are exploring countermeasures to help preserve immune health in space. [Source: Nature]