What Are Tear Ducts?

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Tear ducts, also known as "nasolacrimal ducts," make it possible for tears to drain through the maxillary bone and into the back of the nose. Tear ducts are an important component of eye health, and are also prone to blockage: something that requires medical attention.

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Structure of Tear Ducts

Tear ducts are part of the nasolacrimal system, which is responsible for draining tears from the surface of the eye.

The process begins in the lacrimal glands, which are located in the outer upper corner eye socket on each side of the eye. When a person blinks, it spreads their tears over the surface of their eye. From there, the tears drain into puncta—which are tiny holes located in the corners of the upper and lower eyelids—and then through small drainage canals called canaliculi that lead into the lacrimal sac (also known as the tear sac), which is attached to the side of the nose. The lacrimal sac lies in the lacrimal fossa; the sac drains into the nose via the nasolacrimal duct. At that point, the tears will either evaporate or be reabsorbed.

Why You Get a Runny Nose When You Cry

When we cry—either for emotional reasons or as a response to an irritant—we may find ourselves reaching for the tissues. Tears not only cascade down our faces, but our nose is likely to run, too. This happens because all tears drain through your nose.

While our everyday tears keep our eyes moist and keep germs and debris out, the tears usually evaporate or are reabsorbed before we notice them. But when we're crying because we're upset, or from chopping onions, this produces more tears. More tears mean that they start flowing out of our nose at a rate that's faster than they can be reabsorbed or evaporate, and so they emerge from our body in the form of a runny nose.

Function of Tear Ducts

As described above, the purpose of tear ducts is to transport tears from the eye, where they are produced, into the nose, where they exit the body or are swallowed. Tear ducts are important because they allow for the natural tears your body produces every day to be able to drain. And it's not only the tears you produce when you cry for emotional reasons: these are your everyday maintenance tears that we don't typically notice or think about unless something goes wrong (which we'll get into in detail later).

So why do we need tears in the first place? Overall, tears serve several functions—from keeping the eye clean and healthy to communicating your emotions—and most people produce 15 to 30 gallons of tears each year. For now, let's take a look at the three different types of tears our body produces and their functions:

  • Basal tears: These are everyday maintenance tears that are always in your eyes in order to lubricate, nourish, and protect your cornea. They provide a barrier between the eye and your environment, flushing dirt and debris away.
  • Reflex tears: These are formed when your eyes need to remove some type of irritant, like smoke, very cold temperatures, or fumes from things like chemicals and onions. Reflex tears are produced in greater quantities than basal tears, and may also contain more antibodies to help fight bacteria.
  • Emotional tears: These are the tears that are produced when we cry from having an emotional response involving sadness, anger, fear, or joy (among other emotional states).

Problems With Tear Ducts

When tear ducts are blocked, it throws off the entire nasolacrimal system and doesn't allow for our tears to effectively drain into the nose. This can lead to symptoms like watery eyes or dacryocystitis, which is an infection of the tear sac. Here's what happens when tear ducts are blocked in infants and adults.

Blocked Tear Duct in Infants

Many babies are born with a blockage of their tear ducts, meaning that the tears they produce can't drain out through their nose. This happens when a baby's tear-duct system isn't fully developed. Most frequently, in situations like these, there is usually a membranous covering at the exit of the nasolacrimal duct system.

It is also possible for older children to get clogged tear ducts. This is typically caused by a polyp (extra tissue) in the nose, a cyst or tumor in the nose, or an eye injury.

When infants under six months old have blocked tear ducts, they usually clear up on their own. If they don't, it's possible for parents to learn how to massage their baby's face from their healthcare provider, in an attempt to open the blockage. If that doesn't work, your pediatrician will likely recommend that your child see an ophthalmologist, who will be able to do a more complete assessment of the cause of the blockage. In some cases, surgery is required to treat the clogged tear duct.

Babies Born With Tear Duct Blockage

An estimated 20% of newborns come into this world with a blocked tear duct. This is referred to as a congenital blocked tear duct. In most cases, the condition usually resolves itself within four to six months—though if your baby's tear ducts are blocked for longer than that, it's definitely something to bring up with the pediatrician.

Blocked Tear Duct in Adults 

Blocked tear ducts in adults are typically caused by nasal trauma, sinusitis, history of sinus surgery, punctal plug placement, or severe conjunctivitis, amongst other things. It is also common in postmenopausal women as an age-related change. These blockages can also happen as a result of chronic sinusitis (or other nose-related infections), which can irritate the tissues and form scars, causing tear ducts to become blocked.

The symptoms of a blocked tear duct in adults are typically having exceptionally watery eyes or tears coming out of your eyes without a direct cause (like emotional crying or exposure to an irritant). But it's also possible for bacteria to be trapped in the nasolacrimal sac, which can lead to an infection called dacryocystitis. The symptoms of an infection caused by a tear duct blockage include:

  • Swelling, tenderness, and redness of the inside corner of the eye or around the eye and nose
  • Recurrent eye infections
  • Eye mucus discharge
  • Crusty eyelashes
  • Blurred vision
  • Blood-tinged tears
  • Fever

If you are experiencing any of these symptoms, make an appointment with an ophthalmologist, who will be able to diagnose the condition using one or more tests. Depending on the extent and severity of the blockage, the ophthalmologist may manually drain the tear duct, or in some cases, perform a surgical procedure called a dacryocystorhinostomy, which creates a new route for tears to drain.

Protecting Tear Ducts

If you do find yourself with a blocked tear duct, there are certain common-sense precautions you can take to help it heal faster. These are the same strategies for keeping your eyes safe and healthy if you happen to have pink eye (also known as conjunctivitis). They include:

  • Washing your hands regularly (especially before or after touching your eye)
  • Avoiding rubbing or touching your eyes
  • Replacing any makeup you may have used while infected (and not sharing any makeup with others)
  • Ensuring that you're properly caring for contact lenses, if you wear them (and ideally, switch to glasses for a while)

Smoking and Blocked Tear Ducts

Chronic cigarette smoking can increase a person's risk of having blocked tear ducts. Additional research is required to better understand how smoking impacts tear production and release, but it's yet another reason to quit smoking and get the help you need.

A Word from Verywell

Though we may only think about tears in terms of crying for emotional reasons, they're actually an important part of our overall eye health, and one of those functions that you don't realize you have until something goes wrong (like a blocked tear duct).

If you notice that you have any symptoms of a blocked tear duct, it's best to see your healthcare provider in order to get the treatment you need. Besides, it's a hassle having to constantly explain to people that you're not actually crying.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Raphael G, Raphael M, Kaliner M. Gustatory rhinitis: a syndrome of food-induced rhinorrheaJournal of Allergy and Clinical Immunology. 1989;83(1):110-115. doi:10.1016/0091-6749(89)90484-3

  2. American Academy of Ophthalmology. Facts about tears.

  3. Nemours Kidshealth. Tear-duct blockage.

  4. American Academy of Ophthalmology. What is a blocked tear duct?

  5. American Academy of Ophthalmology. Blocked tear duct causes.

  6. American Academy of Ophthalmology. Blocked tear duct symptoms.

  7. American Academy of Ophthalmology. Blocked tear duct treatment.

  8. Centers for Disease Control and Prevention. Protect yourself from pink eye.

  9. Wang S, Zhao H, Huang C, et al. Impact of chronic smoking on meibomian gland dysfunction. PLoS One. 2016;11(12). doi:10.1371/journal.pone.0168763

By Elizabeth Yuko, PhD
Elizabeth Yuko, PhD, is a bioethicist and journalist, as well as an adjunct professor of ethics at Dublin City University. She has written for publications including The New York Times, The Washington Post, The Atlantic, Rolling Stone, and more.