What are the top risks?

Low-gravity conditions and other spaceflight stressors can alter the heart and blood vessels, potentially leading to blood clots, heart arrythmias, cardiovascular disease, and low blood pressure which elevates the chances of fainting at landing. The risk of developing these conditions will increase with longer-duration missions such as a multi-year trip to Mars, so research focused on understanding and treating these risks is a priority for NASA.

What can be done about it?

Regular exercise and healthy diets help crews maintain cardiovascular fitness. Lower-body compression garments and drinking lots of fluids prior to landing can help to prevent low blood pressure. For future Mars missions, astronauts will also receive enhanced training to respond to cardiovascular emergencies.

Did you know?

Low gravity can also physically change the shape of the human heart, making it become more spherical.

Formal risk description: Risk of cardiovascular adaptations contributing to adverse mission performance and health outcomes

Research in support of this risk: Latest evidence