The more I read about this topic, the more I think people are asking the wrong question.
Most people ask what causes the visible problem.
Very few ask what controls the systems behind it.
That difference matters.
The first mechanism is endothelial function.
Think of it as the traffic controller for blood vessel behavior.
When signaling becomes less efficient, the effects can ripple outward.
The second mechanism is cellular energy production.
Cells are constantly working.
Communication, repair, adaptation—all of it requires energy.
The third mechanism is oxidative stress.
Not because it's trendy to talk about.
Because every signaling system has to operate inside that environment.
What's interesting is that none of these mechanisms work alone.
They constantly influence each other.
Which might explain why two people can experience similar symptoms for completely different reasons.
That possibility seems to get overlooked in most conversations.