A chyle leak occurs when chyle, a nutrient-rich lymphatic fluid, leaks out of lymphatic vessels and collects in areas of the body where it should not. Chyle leaks can affect breathing, nutrition, and immune function and may require ongoing management.
Chyle leaks are seen in some people with lymphatic malformations (LMs) and complex lymphatic anomalies (CLAs), but they do not occur in all patients.
Chyle leaks can also occur in people without an underlying lymphatic condition, most often after surgery, injury, or other conditions that disrupt normal lymphatic flow.
What Is Chyle?
Chyle is a milky lymphatic fluid that carries:
- Fats absorbed from food
- Proteins
- Immune cells
Under normal conditions, chyle travels through the lymphatic system and returns these nutrients to the bloodstream. When lymphatic vessels are abnormal, fragile, or under increased pressure, chyle may leak instead of flowing normally.
Types of Chyle Leaks
When testing confirms that collected fluid is chyle, the medical name reflects both the fluid type and where it is collecting. Common terms include:
- Chylothorax – chyle collecting around the lungs
- Chylous ascites – chyle collecting in the abdomen
- Chylopericardium – chyle collecting around the heart (rare)
These terms help healthcare teams understand that the lymphatic system is involved and guide imaging, nutrition support, and treatment planning.
Why Chyle Leaks Occur
Chyle leaks may occur when lymphatic vessels:
- Are abnormally formed
- Are enlarged or fragile (such as in lymphangiectasia)
- Are under increased pressure
- Are injured, compressed, or obstructed
Not everyone with abnormal lymphatic vessels develops a chyle leak.
How Chyle Leaks Are Diagnosed
Diagnosis usually involves imaging and fluid testing.
- Imaging helps identify where fluid is collecting and whether lymphatic vessels are involved. Common tests include:
- Ultrasound – often the first test; looks for fluid without radiation
- MRI – provides the most detailed view of lymphatic vessels; no radiation
- CT scan – sometimes used for rapid or urgent evaluation
If fluid is drained, testing it for high fat levels confirms that it is chyle. Imaging is then used to help identify the source of the leak.
Treating a Chyle Leak
Treatment focuses on reducing fluid buildup, relieving symptoms, and addressing the underlying lymphatic problem. The approach depends on the severity of the leak and individual patient needs.
Dietary management
- Low-fat or MCT-based diets reduce fat flow through the lymphatic system
- Dietary changes should be guided by a healthcare provider or dietitian
Medications
- May help reduce lymphatic flow or stabilize lymphatic vessels
- Can help control symptoms but do not cure the condition
Fluid drainage
- Relieves pressure on the lungs or organs
- May need to be repeated
- Does not stop the leak itself
Interventional or surgical options
- Considered for severe or persistent leaks
- Typically performed by specialized lymphatic teams
Long-Term Care and Monitoring
Some chyle leaks resolve with treatment, while others require long-term management. Ongoing care may include:
- Symptom monitoring
- Nutrition support
- Regular follow-up with experienced care teams
Care is individualized, and management plans may change over time.
