How does microgravity affect bodily fluids, and what symptoms can occur?

• A. Increased peripheral edema
• B. No change in fluids
• C. Cephalad fluid shift causing facial fullness and potential intracranial pressure changes
• D. Dehydration-only symptoms

Answer: (C)

In microgravity, the usual downward pull of gravity is absent, so bodily fluids shift toward the head. This cephalad fluid shift leads to facial fullness and often nasal congestion, and the increased fluid around the brain can alter intracranial pressure dynamics, which can cause headaches and, in some cases, vision changes. This combination of facial fullness and potential intracranial pressure changes is the most characteristic fluid-related effect in space, making it the best description of the symptoms.