ED is usually caused by low blood flow to the penis or a problem with the nerves that control erections. This is a result of other conditions, such as hardening of the arteries, high blood pressure, and high cholesterol or diabetes.

Why is my erection not as strong sometimes?

The blood vessels in the penis are smaller than arteries in other parts of your body, so any problems like blockages, blood vessel dilation issues, or hormone imbalances will sometimes show up as erectile dysfunction (or less firm erections) before something more serious like a heart attack or stroke.