The trachea is a tube-like structure within the neck and upper chest. It transports air to and from the lungs when a person breathes.

When a person inhales, air travels through the nose or mouth, down the trachea, and into the lungs.

When the lungs expel the air, it travels back up the trachea and out through the mouth or nose.

Keep reading for more information about what the trachea is, what it does, and which health conditions can affect it.

The trachea is a hollow, tube-like structure that runs from the larynx, or voice box, to the bronchi — the two passageways that connect the trachea to the lungs.

The average length of the trachea is about 11.8 centimeters, and a male’s trachea is typically longer than a female’s.

A mucous membrane, similar to those in the nasal cavity, lines the interior of the trachea. Cells in this membrane, called goblet cells, release mucus to help prevent microorganisms and debris from entering the lungs.

The trachea is also lined with tiny hair-like structures called cilia. These help push mucus that contains debris or pathogens out of the trachea. A person then either swallows or spits out the mucus.

Soft tissue makes up most of the trachea, and cartilage provides extra support.

The trachea runs parallel to the esophagus and lies just in front of it. The back of the trachea is softer to allow the esophagus to expand when a person is eating.

Due to their proximity, a small piece of cartilage in the larynx automatically covers the opening of the trachea to prevent food or drink from getting into it when the person is eating.

If food or drink do get into the trachea, this typically causes the person to cough. If a piece of food is particularly large, it could become trapped in the trachea and obstruct breathing.

The primary function of the trachea is to transport air to and from the lungs. Without a trachea, a person would not be able to breathe.

In addition to transporting air, the trachea helps defend against disease. The mucus in the trachea helps capture microorganisms such as viruses and harmful bacteria before they enter the lungs.

The trachea also helps regulate the temperature of the air coming in and out of the lungs.

On cold days, the trachea helps warm and provide humidity to the air before it reaches the lungs.

On hot days, the trachea helps cool the air through evaporation.

Various health conditions can affect the trachea. In serious cases, a person may have trouble breathing and require immediate medical attention.

Some conditions that can affect the trachea include:

  • Tracheomalacia, a condition in which the cartilage of the trachea has broken down, causing weakness or floppiness of the trachea that can affect breathing.
  • Tracheal stenosis, narrowing of the trachea that causes mild to severe breathing problems. If the narrowing is severe, a person may require a tracheal tube.
  • Tracheal tumors, which are rare. Whether or not these tumors are cancerous, they can cause the trachea to narrow, making breathing more difficult.

There are several potential causes of tracheomalacia. They can include:

  • inhaling irritants
  • gastroesophageal reflux disease, or GERD
  • chronic infections that affect the trachea, such as bronchitis
  • emphysema
  • surgical damage
  • damage from long-term use of a breathing tube

Some potential causes of tracheal stenosis include:

  • trauma to the chest or throat
  • a tumor pushing against the trachea
  • damage from radiation therapy
  • certain infections, such as tuberculosis
  • some autoimmune disorders
  • pressure from other bodily structures in the neck or chest

If a health problem is affecting their trachea, a person may experience:

  • trouble breathing or catching their breath
  • wheezing
  • stridor, a squeaking or whistling sound when a person breathes
  • otherwise noisy breathing
  • hoarseness
  • a bluish skin tone
  • coughing
  • trouble swallowing food
  • coughing up blood

A person should seek emergency medical help if they have difficulty breathing.

If coughing or shortness of breath is a persistent concern without a clear cause, speak with a doctor.

The trachea’s primary purpose is to transport air to and from the lungs.

It also helps prevent microorganisms, debris, and air that is too cold or too hot from entering the lungs.

If a person is having trouble breathing, a health problem may be affecting their trachea, and they should seek medical attention as soon as possible.