What causes bloodshot eyes? Is it a disease?

I believe many of my friends have experienced bloodshot eyes. Most of the time, it is caused by excessive use of the eyes, and it can be relieved by getting more rest. However, there are some eye diseases that can cause eye congestion, such as conjunctivitis, iritis, allergies, etc., which need to be diagnosed and treated in time.

Causes of bloodshot eyes:

1. Eye congestion caused by infection

When infected by bacteria, rickettsia, viruses, fungi, parasites, etc., it can cause keratitis, corneal ulcers, uveitis, purulent iridocyclitis, endophthalmitis, panophthalmitis, orbital cellulitis, etc., as well as various types of conjunctivitis. These inflammations can cause symptoms of eye congestion.

2. Eye congestion caused by allergic reaction

When the human body is allergic to foreign antigens, allergic to self-antigens, or has an autoimmune disease, symptoms of eye congestion will appear. Common causes include allergies to drugs such as atropine, bullous keratoconjunctivitis, vernal cardia conjunctivitis, stromal keratitis, scleritis, iridocyclitis, etc.

3. Eye congestion caused by eye injury

When the eyes are hit or something unusual enters them, such as being hit in the eyes, or something enters the eyes when removing eye makeup, this will cause the eyes to become congested for a short period of time.

4. Eye congestion caused by compression

When the pressure inside the eye or orbit increases, it will cause blood circulation disorders in the eye and local congestion, so the eyes will have symptoms of congestion. This situation is common in patients with acute angle-closure glaucoma or orbital space-occupying lesions.

5. Eye congestion caused by intraocular neoplasms

When active pterygium or malignant tumors of the cornea and conjunctiva grow in the human eye, the eye will become congested. In this case, the patient needs timely treatment to prevent the neoplasm from affecting vision.