Does Dehydration Cause ED to contribute to erectile dysfunction (ED)? When the body is dehydrated, it can lead to reduced blood volume and circulation, which may affect the ability to achieve and maintain an erection. Additionally, dehydration can impact hormone levels, including Testosterone, which plays a role in sexual function. Adequate hydration is important for maintaining healthy blood flow, which is crucial for an erection. Staying well-hydrated is important for overall health and can support sexual function.