Crying does more than produce tears. For many people, it also causes a runny nose, nasal congestion, sneezing, or the need to sniff repeatedly. The reason is simple once you understand how the eyes and nose are connected: some of the tears your eyes produce drain into your nose.
When you cry, your tear glands produce more fluid than they normally do. Part of that fluid spills over the eyelids, forming the tears you see on your face. Another portion drains through tiny openings near the inner corners of your eyes and travels through the tear drainage system into the nasal cavity. Once there, the fluid mixes with normal nasal mucus, making your nose feel wet and causing it to run.
The process is normal and usually stops as the crying subsides.
Your eyes and nose are connected
Your tears do not simply disappear from the surface of your eyes. Under ordinary circumstances, tears continuously lubricate and protect the eyes, and excess fluid drains away through small openings called puncta. There is typically one near the inner corner of each upper and lower eyelid.
From the puncta, tears enter small channels called canaliculi. They then pass into the lacrimal sac and through the nasolacrimal duct, a drainage passage that empties into the nasal cavity.
This is why your nose can become watery even though the fluid began in your eyes.
You can sometimes notice this connection without crying. If you have ever tasted a slightly salty or bitter fluid in the back of your throat after your eyes water, some tear fluid may have traveled through the drainage system and toward the throat.
What changes when you cry
Your eyes normally produce a small, steady amount of tears. Emotional crying dramatically increases tear production. The drainage system can carry away some of this extra fluid, but it cannot necessarily handle all of it immediately.
The excess tears therefore have two possible destinations: they spill over the eyelids and run down your cheeks, or they drain into the nose.
Once the tears reach the nasal cavity, they add liquid to the mucus already lining the nose. That produces the familiar watery nasal discharge associated with crying. Because the fluid is coming from the tear drainage system, the discharge is usually thin and watery rather than thick like mucus produced during some respiratory illnesses.
Why you may feel congested, too
A runny nose is the most obvious effect, but crying can also make your nose feel blocked or stuffy.
The inside of the nose contains soft, highly vascular tissue called the nasal mucosa. Emotional crying can be accompanied by changes in blood flow and activity in the tissues around the eyes and nose. In addition, increased fluid in the nasal passages can contribute to the sensation of congestion.
There is also an important behavioral component: when you cry, you tend to sniff, breathe differently, and wipe or rub your nose. Those actions can make nasal symptoms more noticeable.
The exact combination varies from person to person. One person may mainly have watery discharge, while another may become noticeably congested.
Why crying can make you sniff so much
Sniffing is partly a way of moving the fluid that accumulates in the nose and back toward the throat instead of allowing it to run out of the nostrils. It can also help clear the nasal passages temporarily.
After crying stops, tear production gradually returns toward its usual level. The additional fluid entering the nose decreases, and the runny nose generally settles on its own.
This is why the nose may continue running for a short time after you have stopped visibly crying.
Are tears and nasal mucus the same thing?
No. They are different fluids produced by different tissues, although they can mix once tears enter the nasal cavity.
Tears are produced primarily by the lacrimal glands and several smaller glands associated with the eye. They contain water, salts, proteins, and other substances that help lubricate and protect the surface of the eye.
Nasal mucus is produced by cells and glands in the lining of the nasal passages. It helps trap particles, humidify inhaled air, and protect the nasal tissues.
When you cry, extra tear fluid enters the nose and mixes with nasal secretions. The resulting discharge can therefore look and feel different from the tears themselves.
Does everyone get a runny nose when they cry?
No. The effect varies considerably.
How much your nose runs depends partly on how much you cry, how efficiently your tear drainage system moves fluid into the nose, how much nasal mucus you normally produce, and how sensitive your nasal tissues are to changes in fluid and blood flow.
A person’s baseline nasal condition matters, too. Someone with nasal allergies, a cold, irritation, or another cause of nasal inflammation may notice a much stronger runny or congested nose while crying than someone whose nasal passages are otherwise clear.
Why your nose may run even more if you’re already sick
Crying does not cause a cold or other respiratory infection. But if your nose is already inflamed, it may respond more noticeably to the additional fluid.
During a cold, for example, the nasal lining can become swollen and produce more mucus. Allergies can produce a similar increase in nasal secretions and congestion. Adding tears to an already active nasal system can make the sensation of a runny nose particularly obvious.
That distinction matters: the tears explain why crying can make your nose run, while an underlying illness or allergy can explain why the effect is unusually pronounced.
Is a runny nose from crying something to worry about?
Usually, no. A watery nose during or shortly after crying is a normal consequence of the connection between the tear drainage system and the nasal cavity.
It is worth paying attention if nasal drainage occurs persistently when you are not crying, especially if it is accompanied by symptoms such as significant facial pain, fever, persistent blockage, frequent nosebleeds, or other unusual symptoms. Those findings can have causes unrelated to ordinary tear drainage and may warrant medical evaluation.
For ordinary crying, however, a tissue and a little patience are generally all that is needed. The nose runs because the body’s tear-drainage system gives excess tears a route into the nasal passages—and when you produce a lot of tears, your nose notices.
