Causes of bloody tears:
(1) conjunctivitis
(2) vascular disorder of the conjunctiva
(3) primary or metastatic tumor to the conjunctiva, including fibroma and malignant melanoma
(4) subconjunctival hemorrhage
(5) trauma (eyelid, other)
(6) pubic lice involving the eyelashes (
phthiriasis palpebrarum)
(7) hereditary hemorrhagic telangiectasia (HHT)
(8) other type of telangiectasia (focal dermal hypoplasia syndrome (Goltz syndrome, other)
(9) hemophilia or other bleeding disorder
(10) excessive anticoagulation
(11) disorder of a lacrimal gland (tumor, vascular disorder or infection)
(12) severe epistaxis with blood regurgitating through the nasolacrimal duct
(13) corneal pannus or vascular lesion
(14) vicarious menstrual bleeding
(15) severe autonomic dysfunction
With bloody tears examination of a smear should show red blood cells. If tears can be collected then hemoglobin can be measured.
Differential diagnosis:
(1) red colored tears from ingested drugs or chemicals
(2) red colored tears from eye makeup
