What happens to Blood pressure of astronaut in space?
1. Reduced hydrostatic pressure: In the absence of gravity, the hydrostatic pressure gradient that usually causes blood to pool in the lower extremities on Earth is eliminated. As a result, the distribution of blood in the body becomes more uniform, and the blood pressure in the arteries decreases. This decrease is particularly noticeable in the lower body, where the blood pressure can drop by as much as 50%.
2. Headward fluid shift: The reduction in hydrostatic pressure also causes a shift of fluids, including blood, towards the head and upper body. This can lead to increased pressure in the blood vessels of the head, neck, and chest, which can potentially cause problems such as headaches, nasal congestion, and fluid buildup in the lungs.
3. Cardiovascular deconditioning: The lack of gravity in space can lead to cardiovascular deconditioning, which is the weakening of the heart and blood vessels. This is because the heart does not have to work as hard to pump blood against gravity, and the walls of the blood vessels can become thinner and weaker. As a result, the blood pressure can decrease further, and astronauts may experience orthostatic intolerance (difficulty standing up without feeling dizzy or lightheaded) when they return to Earth.
To mitigate the effects of changes in blood pressure, astronauts engage in regular exercise and follow specific protocols for fluid intake and body positioning during their time in space. They also undergo careful monitoring and medical assessments to ensure their health and safety throughout their missions.