HDL cholesterol of 0.78 mmol/L is below the standard range and is abnormal. HDL cholesterol less than 1.0 mmol/L is considered lowered, and normally, HDL cholesterol should be at least greater than 1.0 mmol/L. HDL cholesterol is considered an anti-atherosclerotic plasma lipoprotein and a protective factor against coronary heart disease. HDL cholesterol is the lipoprotein that transports cholesterol from peripheral tissue cells to the liver. Patients found to have low HDL cholesterol can consult a medical professional for consultation and treatment to avoid delays.