Chylothorax is a condition where fluid from your lymphatic system (chyle) leaks into the space around your lungs. Damage to or blockages in your lymphatic vessels in your chest can cause it. Surgery is the most common cause. Treatments include temporary diet changes, draining and surgical procedures.


What is chylothorax?

Chylothorax (pronounced “kai-low-THOR-aks”) is a condition where fluid (chyle) from your lymphatic system leaks into the space around your lungs. Your lymphatic system — a series of vessels similar to your blood vessels — drains extra fluid from your tissues. White blood vessels patrol the fluid (lymph) to look for and destroy germs like bacteria and viruses.

Chyle is a kind of lymph that comes from your digestive tract. It contains a mix of white blood cells and fats that make it look milky. It moves through your body through your thoracic duct. Your thoracic duct is a tube that moves chyle from your abdomen, up through your chest, to your neck. There, it empties back into your bloodstream.

Damage to your thoracic duct can cause it to leak. If it leaks into the space around your lungs, it’s called chylothorax.

Types of chylothorax

Chylothorax is either traumatic, non-traumatic or idiopathic:

  • Traumatic chylothorax happens when the lymph vessels in your abdomen or chest are damaged by force. This could be during surgery or after an injury.
  • Non-traumatic (spontaneous) chylothorax happens when something blocks your lymph vessels, weakens their walls or causes a buildup of chyle that makes the vessels burst. People who have anatomical differences in their chest can be born with non-traumatic chylothorax (congenital chylothorax). They can also develop it a few days after birth.
  • Idiopathic chylothorax is any kind of chylothorax where your provider can’t find the cause.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

Symptoms and Causes

What are the symptoms of chylothorax?

The main symptom of chylothorax is shortness of breath. Some people also experience:

  • Chest pressure, tightness or heaviness.
  • Tiredness (fatigue).
  • Unintended weight loss.

What’s the most common cause of chylothorax?

Surgery is the most common cause of chylothorax (postoperative chylothorax). But anything that can damage your thoracic duct, which carries chyle, can cause chylothorax. Damage can cause chyle to leak from your lymphatic system into your chest. Other causes include:

  • Injury to your chest or back. This includes blunt trauma injuries (something hitting your body hard) and injuries that break through your skin (like a stab wound).
  • Present at birth. Differences in anatomy and certain illnesses you’re born with can cause chylothorax. Babies either have it at birth (congenital) or develop it in the first few days after birth.
  • Many cancers can block or damage structures in your chest, allowing chyle to leak. This includes lymphoma, chronic lymphocytic leukemia, lung cancer, esophageal cancer, Kaposi sarcoma and others.
  • Sometimes, infections can damage the ducts that carry chyle, allowing it to leak. Tuberculosis is the most common cause of this kind of chylothorax.
  • Blockage. Anything that can cause conditions that block your thoracic duct can lead to chylothorax. This includes sarcoidosis, blood clots and goiter.

What are the risk factors for chylothorax?

You might be at higher risk for chylothorax if you:

  • Had recent surgery to your chest, neck or abdomen. This includes lung and cardiovascular (heart or blood vessel) surgery.
  • Had an injury to your chest or back.
  • Have cancer or a condition that can cause blockages in your chest or buildup in your lymphatic system.

Diagnosis and Tests

How is chylothorax diagnosed?

After listening to your symptoms and health history, a healthcare provider diagnoses chylothorax with imaging tests and by testing a sample of fluid from your chest.

What tests will be done to diagnose chylothorax?

A provider may perform or order these tests to diagnose chylothorax:

  • Imaging. Your provider needs to see pictures of the inside of your chest to know if excess fluid is causing your symptoms. They might use X-rays, ultrasounds or CT scans.
  • Thoracentesis. Your provider might drain fluid from your chest and test it. This tells them more about what the fluid is and what might be causing it to leak.
  • Lymphangiography or lymphoscintigraphy. These are special imaging tests to look at your lymphatic system.

Management and Treatment

How is chylothorax treated?

How your provider treats chylothorax depends on the cause. They may suggest a special diet or drain the fluid first. If those don’t work, they may use a surgical procedure to seal the leak (lymphangiogram and embolization) or to keep the fluid from leaking again. Treating the underlying cause of chylothorax is the best way to keep it from coming back.

Specific therapies that treat chylothorax

Your provider may recommend the following treatments:

  • Bowel rest. Your lymph vessels that transport chyle may need a break so they can heal. To do this, your provider will give you all of your nutrition through an IV. This gives your body a rest from breaking down food through your digestive system.
  • Dietary changes. To help give your body a break from digesting fats, a dietitian can guide you through a very low-fat or modified-fat diet. This is only temporary. Limiting healthy fats in your diet for too long can lead to malnutrition.
  • Draining fluid. A provider may drain the fluid from your chest using thoracentesis. They might drain it once or over a short period of time with a chest tube. While it can’t repair damage on its own, this can relieve symptoms while your body heals.
  • Somatostatin or octreotide. These are IV medications that change how your body absorbs fats and nutrients. Providers sometimes use them in combination with other treatments, like diet changes, to help your body heal.
  • Thoracic duct ligation or embolization. If your thoracic duct is damaged or doesn’t work properly, a provider may surgically tie it off (ligation) or purposefully block it (embolization). This can repair damage or redirect the flow of fluid so it doesn’t leak.
  • Pleurodesis. Pleurodesis is a surgical procedure that sticks your lungs to the lining on the inside of your chest wall. This gets rid of the space inside your chest where the fluid is collecting.

Outlook / Prognosis

What can I expect if I have chylothorax?

What you can expect with chylothorax depends on what’s causing it and how well you respond to treatment. Mild leaks can sometimes heal on their own or with temporary dietary changes. But you might need surgery to fix the damage. Ask your provider what to expect in your specific situation.

Is chylothorax life-threatening?

Chylothorax can be life-threatening if left untreated. It can also be caused by serious illnesses. You may need ongoing treatments for underlying illnesses.

Living With

What can’t I eat/drink with chylothorax?

Your provider may suggest you go on a special diet if you have chylothorax. This includes eating and drinking foods and beverages with very little fat or specific kinds of fats.

They may also recommend that you not eat at all. In this case, you’ll get all of your nutrition in an IV, giving your body time to heal. In either case, you should be able to return to your normal diet within a week or two.

When should I see my healthcare provider?

See your healthcare provider if you have unexplained shortness of breath, especially if you:

  • Had surgery recently.
  • Had a recent injury to your chest or back.
  • Have a condition that can cause blockages in your chest or neck.
  • Have a condition that affects your lymphatic system.

When should I go to the ER?

Go to the nearest emergency room if you have trouble breathing, especially if you also have chest pain. This could be a sign of a life-threatening illness.

What questions should I ask my doctor?

It might be helpful to ask your provider:

  • What caused this?
  • What are my treatment options?
  • What should/shouldn’t I eat or drink?
  • Is there any way to prevent this from happening again?
  • How long will it take to feel better?

Additional Common Questions

What’s the difference between chylothorax and pleural effusion?

Pleural effusion is any fluid in the pleural space (space between your lungs and your chest wall). Chylothorax is a specific kind of pleural effusion where chyle leaks into the pleural space.

A note from Cleveland Clinic

Chylothorax is a rare but potentially life-threatening condition if left untreated. Surgery is the most common cause, but anything that blocks or damages your thoracic duct can also cause it. Temporary diet changes, IV nutrition and medications can successfully treat chylothorax in many people. Others might need surgical treatments. Your provider will talk to you about the best options for your specific situation.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 04/20/2023.

Learn more about our editorial process.

Appointments 800.659.7822