Medical conditions such as blepharitis, episcleritis, iritis and uveitis cause bloodshot eyes, according to the Mayo Clinic. Additional causes for red, irritated eyes include hay fever, viral or bacterial conjunctivitis, corneal ulcers and injury.
People must seek medical attention if symptoms such as constant eye pain, headaches and nausea, vision loss or sensitivity to light occur, advises the Mayo Clinic. Viral and bacterial conjunctivitis cause mucous and pus to leak from eyes, while an eye injury typically causes sharp, constant pain. Blepharitis causes burning and itching around eyes, while uveitis can lead to vision problems and pain, reports About.com.
Remedies for bloodshot eyes caused by dry eye, allergic reactions and irritation from foreign objects include cold compresses, eye drops and artificial tears, claims About.com. Cold compresses help reduce the size of blood vessels in the eyes and reduce swelling. Eye drops that contain an antihistamine reduce itching, which helps reduce eye redness. Artificial tears also help reduce itching and eye redness.
Allergy medications, regular eye exams and clean contact lenses help reduce the occurrence of bloodshot eyes, states AllAboutVision.com. It is also important to clean eyelids often to prevent bacteria build-up. It helps to take frequent breaks when using computers and other electronic devices, and to avoid touching and rubbing the eyes.