​Did you know that even short-term anti-gravity experience can temporarily affect coordination and spatial orientation? (Image: Gemini). Imagine stepping into a room where gravity doesn’t exist. You’re floating, weightless — but inside your body, things are shifting rapidly. While 24 hours in zero gravity wouldn’t cause permanent damage to a healthy person, it would trigger noticeable changes in circulation, balance, and brain function. Here’s how your body will feel within 24-hours in an anti-gravity room.. First reaction: Blood rushes upward. “If a healthy person were exposed to zero gravity for 24 hours, the body would begin adapting within minutes,” says Dr RR Dutta, HOD, Internal Medicine, Paras Health, Gurugram. On Earth, gravity pulls blood toward the legs. In weightlessness, that pull disappears. Blood and other fluids shift toward the chest and head, causing what many describe as facial puffiness, nasal congestion, and sometimes a mild headache.. “In the initial hours, blood that normally pools in the lower limbs shifts toward the chest and head due to the absence of gravitational pull,” Dr Dutta explains. The body interprets this as excess fluid and responds by increasing urine output. As a result, plasma volume begins to decrease within the first 24 hours. This redistribution is one of the earliest hallmark responses to weightlessness.. Heart and blood pressure changes. Without gravity, the heart doesn’t have to work as hard to pump blood upward. “Weightlessness reduces the effort required for the heart to pump blood to the brain and upper body,” Dr Dutta notes. There may be mild fluctuations in blood pressure initially, and as plasma volume reduces, blood pressure may trend slightly lower. However, over 24 hours, these cardiovascular changes remain subtle and are usually well tolerated in healthy individuals.. Importantly, one day isn’t long enough to cause muscle wasting or bone loss. “Muscle atrophy and bone demineralisation require sustained absence of mechanical loading over days to weeks,” he clarifies. While early signalling may begin, there would be no measurable weakness in just 24 hours.. “Ithe initial hours, blood that normally pools in the lower limbs shifts toward the chest and head due to the absence of gravitational pull”: Dr RR Dutta (Image: Gemini). Also Read | ‘You can easily create a mess’: As astronaut Shubhanshu Shukla says he ‘ate water in space,’ expert lists digestive challenges in microgravity. Your brain loses its reference point. From a neurological perspective, zero gravity is deeply disorienting. “The brain constantly relies on inputs from the inner ear, eyes, muscles, and joints to maintain posture and orientation,” says Dr Pooja Anand, Consultant – Neurology, Paras Health, Gurugram. “In the absence of gravity, this coordinated system is suddenly disrupted.”. The inner ear’s vestibular apparatus — especially the otolith organs that sense gravity — st