What are the symptoms of blocked tear duct?

When you have a blocked tear duct, your tears can't drain normally, leaving you with a watery, irritated eye. Blocked tear ducts are caused by a partial or complete obstruction in the tear drainage system.
Blocked tear ducts are common in newborns, but they usually get better without any treatment during the first year of life. In adults, a blocked tear duct may be due to an injury, infection or a tumor.
A blocked tear duct almost always is correctable. Treatment depends on the cause of the blockage and your age.

Symptoms

Signs and symptoms may be caused by the blocked tear duct or from an infection that develops because of the blockage. Look for:

Excessive tearing
Recurrent eye inflammation (conjunctivitis)
Recurrent eye infections
Painful swelling near the inside corner of the eye
Mucus or  pus discharge  from the lids and surface of the eye
Blurred vision
When to see a doctor

If your eye has been watery and leaking or is continually irritated or infected, make an appointment to see your doctor. Some blocked tear ducts are caused by tumors pressing on the tear drainage system, and quick identification of the tumor can give you more treatment options.

Causes

The lacrimal glands produce most of your tears. These glands are located inside the upper lids above each eye. Normally, tears flow from the lacrimal glands over the surface of your eye. Tears drain into tiny holes (puncta) located in the corners of your upper and lower eyelids.

Your eyelids have small canals (canaliculi) that move tears to a sac where the lids are attached to the side of the nose (lacrimal sac). From there, tears travel down a duct (the nasolacrimal duct) draining into your nose. Once in the nose, tears are reabsorbed.

A blockage can occur at any point in the tear drainage system, from the puncta to your nose. When that happens, your tears don't drain properly, giving you watery eyes and increasing your risk of eye infections and inflammation.

Blocked tear ducts can happen at any age. They may even be present at birth (congenital). Causes include:

Congenital blockage. Many infants are born with a blocked tear duct. The tear drainage system may not be fully developed or there may be a duct abnormality. A thin tissue membrane often remains over the opening that empties into the nose (nasolacrimal duct) in congenitally blocked tear ducts. This usually opens spontaneously during the first or second month of life.
Age-related changes. As you age, the punctal openings may get narrower, causing partial blockage that slows the flow of tears into the nose, resulting in tearing. Total blockage of the punctal openings also may occur.
Eye infections or inflammation. Chronic infections and inflammation of your eyes, tear drainage system or nose can cause your tear ducts to become blocked.
Facial injuries or trauma. An injury to your face can cause bone damage near the drainage system, disrupting the normal flow of tears through the ducts.
Tumors. Nasal, sinus or lacrimal sac tumors can occur along the tear drainage system, blocking it as they grow larger.
Topical medications. Rarely, long-term use of certain topical medications, such as some of those that treat glaucoma, can cause a blocked tear duct.
Cancer treatments. A blocked tear duct is a possible side effect of chemotherapy medication and radiation treatment for cancer.
Risk factors

Certain factors increase your risk of developing a blocked tear duct:

Age and sex. Older women are at highest risk of developing blocked tear ducts due to age-related changes.
Chronic eye inflammation. If your eyes are continually irritated, red and inflamed (conjunctivitis), you're at higher risk of developing a blocked tear duct.
Previous surgery. Previous eye, eyelid, nasal or sinus surgery may have caused some scarring of the duct system, possibly resulting in a blocked tear duct later.
Glaucoma. Anti-glaucoma medications are often used topically on the eye. If you've used these or other topical eye medications, you're at higher risk of developing a blocked tear duct.
Previous cancer treatment. If you've had radiation or chemotherapy to treat cancer, particularly if the radiation was focused on your face or head, you're at higher risk of developing a blocked tear duct.

Complications

Because your tears aren't draining the way they should, the tears that remain in the drainage system become stagnant, promoting growth of bacteria, viruses and fungi. These organisms can lead to recurrent eye infections and inflammation. Any part of the tear drainage system, including the clear membrane over your eye surface (conjunctiva), can become infected or inflamed because of a blocked tear duct.