High cholesterol does not show any visible symptoms and can only be diagnosed by a blood test. Reference: Mayo Clinic: https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/symptoms-causes/syc-20350800 NHLBI: https://www.nhlbi.nih.gov/files/docs/public/heart/chol_tlc.pdf CDC: https://www.cdc.gov/cholesterol/facts.htm
