[header] How to thicken blood before surgery [title] Alter your diet one to two weeks in advance. [step] It can take days or weeks for the thickness of your blood to change due to dietary and lifestyle habits alone. Start making these changes as early as possible to maximize the potential impact they have on your blood. 
[substeps] Talk to your doctor before altering your diet. They'll be able to give you specific instructions about any dietary changes you should make before your surgery.