Consider symptoms plus testing. Clinically, easy bruising, gum/nose bleeding, heavier menstrual bleeding, or prolonged bleeding from minor injuries can be clues. Lab work may show prolonged clotting times (notably PT/INR), but these tests are not specific and can be influenced by liver disease, medications, or other deficiencies. Clinicians assess diet, antibiotic/anticoagulant use, and conditions affecting fat absorption (gut, bile, liver). The goal is to identify the underlying cause and tailor nutrition or treatment accordingly.