Does Dehydration Cause ED to affect your body in several ways, and one of those is its impact on erectile function. Simply feeling unwell or uncomfortable due to dehydration can distract you and make it harder to focus on sexual activity. Dehydration can lead to imbalances in electrolytes like potassium and sodium, which are important for nerve function and muscle control, including those involved in erections. Dehydration decreases blood volume, which can affect circulation. Adequate blood flow is crucial for achieving and maintaining an erection.