MECHANISM ENGINE
What Is HDL Cholesterol?
HDL got called the good cholesterol for years, and I took that at face value, higher is better, job done. Turns out it’s a bit more particular than that.
The Hoover With a Motor That Has to Actually Work
HDL’s job is to go round the bloodstream picking up excess cholesterol from artery walls and ferrying it back to the liver to be dealt with, a bit like a hoover doing the rounds of the house. Having a hoover in the cupboard isn’t the same as having one that switches on and actually picks anything up. A high HDL number on paper is the hoover in the cupboard. Whether it’s functioning properly, actually shifting cholesterol rather than just sitting there, is a separate question the standard test doesn’t fully answer. It’s a useful number. It’s just not the whole story on its own.
HDL, high-density lipoprotein, transports cholesterol away from artery walls and tissues back to the liver for processing, a process called reverse cholesterol transport. This is why it’s generally considered protective. HDL levels respond to lifestyle factors including regular movement, non-UPF eating, and reduced alcohol intake, with exercise being one of the more consistently evidenced levers for raising it.
NHS guidance considers HDL above 1 mmol/L for men and 1.2 mmol/L for women broadly protective, though the whole lipid panel, not HDL alone, is what informs cardiovascular risk assessment.
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Related mechanisms
Educational content only, not medical advice. Never stop or change medication without your GP’s supervision. Neil stopped his own medications in February 2024 on his own initiative and told his GP afterwards. That’s not the approach recommended here.
What this is based on
NHS and NICE guidance, cross-referenced against Neil’s own NHS blood test record going back to April 2012. See the full timeline and current numbers.