Lymphangioleiomyomatosis (LAM) is a disease of the lungs, blood vessels, and lymphatic system. It almost exclusively affects biological females. Much of the time, it’s part of an inherited condition called tuberous sclerosis complex (TSC).

In LAM, an unusual type of muscle cell grows into the airways, as well as the blood vessels and lymph vessels. There, these cells form clusters that can cause blockages. These cells aren’t cancerous, but they can lead to serious problems.

In this article, you’ll learn about LAM's symptoms and causes, how it’s diagnosed and treated, and how to live well with it.

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Breaking It Down

  • Lymph = Lymphatic system
  • Angio = Blood vessels
  • Leiomy = Smooth muscle
  • Oma = Tumor
  • (T)osis = Condition

So, the word "lymphangioleiomyomatosis" means “a condition with smooth-muscle tumors in the blood and lymphatic vessels.”


LAM symptoms are most likely to begin in your 30s or 40s. It’s often a slowly progressing disease. 

Early symptoms may include:

  • Shortness of breath or wheezing
  • Fatigue
  • Cough
  • Low oxygen levels

Because these symptoms are typical of other lung diseases, such as asthma, it may be challenging for healthcare providers to recognize them.

Other symptoms that occur in LAM include:

  • Stabbing pain in the chest
  • Labored, rapid breathing
  • Rapid heartbeat
  • Low blood pressure
  • Profuse sweating
  • Dizziness
  • Lack of normal breathing movement on one side of the chest

These symptoms may happen when cysts in the lung rupture and cause a pneumothorax (collapsed lung). This means that air has leaked out and filled the space between the lung and chest wall. This complication of LAM requires emergency medical treatment.

If LAM cysts block blood vessels, you may develop a pulmonary hemorrhage (bleeding into the lungs) and cough up blood.

If cell clusters block lymphatic vessels, it can lead to an abnormal collection of fluid in your chest or abdomen.

You may develop a type of benign (noncancerous) tumor called angiomyolipomas. These tumors are most common in the kidneys. They don’t always cause symptoms, but when they do, symptoms may include:

  • Flank pain
  • Blood in the urine
  • Bleeding into the abdomen

LAM flares are commonly tied to hormonal events. Pregnancy, hormonal birth control, and the menstrual cycle can all trigger flares. Symptoms often stabilize after menopause.

When the disease is advanced, it can permanently damage your lungs and lead to respiratory failure, which is life-threatening.

Rapid Progression

Rarely, LAM may progress quickly. Researchers don’t yet understand why this happens.

Causes of LAM Disease

LAM is caused by gene mutations.

TSC is a rare genetic disorder that’s generally discovered soon after birth. It causes most cases of LAM. If you don’t have TSC but develop LAM, it’s called sporadic (S-LAM).

Tuberous sclerosis complex and lymphangioleiomyomatosis are caused by random mutations in one of two genes, TSC1 and TSC2. These genes are involved in creating proteins that regulate cell size and growth.

When your body can’t make these proteins, cells can grow and divide out of control. This leads to tumors and cysts.

So far, researchers can’t say for sure why LAM occurs almost exclusively in females. They suspect estrogen (the primary female sex hormone) may play a role.


Diagnosing LAM is difficult, in part because symptoms are similar to those of other lung diseases. Healthcare providers use a variety of tools to reach the diagnosis.


Chest X-rays are a common first step when looking into causes of breathing problems, like those possible with LAM. They can help diagnose a variety of illnesses, including pneumonia, emphysema, and lung cancer.

Your healthcare provider may order a chest X-ray to rule out these and other conditions or to diagnose a collapsed lung or fluid in the chest cavity. However, an X-ray isn’t usually great for diagnosing LAM.

CT (computed tomography) scans can show the distinct structures of LAM cysts/tumors. Combined with symptoms, this provides a diagnosis in more than 80% of cases.

Additional Tests

When a healthcare provider can’t make a definitive diagnosis based on symptoms and a CT scan, they may order additional tests. These include:

  • Blood tests: These can detect the growth of cells frequently involved in LAM tumors and whether blood oxygen levels are low.
  • Lung biopsy: Tissue is removed and studied, which can show LAM cysts and tumors, fluid in the lung, and collapsed lung.
  • Pulmonary function tests: You breathe into a machine that measures lung function, which is more useful for monitoring LAM than for diagnosis.

Your provider may order other tests as well, depending on your symptoms.

Prevalence of LAM

TSC affects 1 in every 6,000 newborns in the United States, and about 30% of them will someday develop LAM. Sporadic LAM affects between 3 and 8 people out of every 1 million.

Treatment Options

Lymphangioleiomyomatosis is a chronic (lifelong) disease with no cure. But treatments can help you manage it well, keep it from progressing, and prevent complications.

Medications that can help improve lung function in LAM include Rapamune (sirolimus) and Afinitor (everolimus). To help you breathe better, you may be given an inhaled bronchodilator, which is used to treat asthma.

For advanced cases, treatment may include:

Because of the possible link with estrogen, hormonal treatments used to be routine for LAM. However, they’ve been declared ineffective and potentially harmful, so they’re no longer recommended.

Living With LAM Lung Disease

Early on, LAM symptoms tend to have a very low impact on lifestyle. The main recommendations are to:

  • Follow a healthy diet. 
  • Get routine exercise.
  • Don’t smoke, and avoid secondhand smoke.
  • Stay up-to-date on immunizations.
  • If taking LAM drugs, avoid live virus vaccines.
  • Avoid estrogen-containing contraception and hormone replacement therapy.
  • Ask your healthcare provider if you need to take special precautions when flying.
  • If you are or want to be pregnant, talk to your healthcare provider about what to expect.

LAM may become more limiting as the disease progresses. Breathing difficulties may limit your activity level, and you may need supplemental oxygen some or all of the time.

Expect to have regular lung-function tests and imaging to monitor disease progression and treatments. Let your healthcare provider know if you have new, changing, or worsening symptoms.


Lymphangioleiomyomatosis is a chronic, rare disease that causes abnormal, noncancerous growths in the lungs, blood vessels, and lymphatic vessels. The primary symptoms are cough and shortness of breath. Complications include a collapsed lung and fluid in the lungs.

LAM is caused by a genetic mutation. It removes controls for how your cells grow and divide, which leaves them multiplying out of control. It’s diagnosed mainly through CT scans, blood work, and sometimes a lung biopsy.

Treatments include medications, oxygen therapy, pulmonary rehabilitation, and lung transplant. To help manage it, live a healthy lifestyle, don’t skip immunizations, and talk to your healthcare provider about pregnancy and contraception.

A Word From Verywell 

Being diagnosed with a chronic, progressive lung disease may leave you with a lot of difficult emotions. This is a normal response. If you need help working through these feelings, talk to your healthcare provider. They can connect you with helpful resources.

You also might want to look for a support group online or in your community. Because LAM is rare, consider those that deal with similar lung conditions or lung disorders in general.

Frequently Asked Questions

  • Is lymphangioleiomyomatosis curable?

    No, LAM isn’t curable. However, it can be well treated and managed with medications, inhalers, oxygen therapy, and pulmonary rehabilitation. Lung transplants are an option in the most advanced cases.

  • Is LAM disease contagious?

    No, LAM isn’t contagious. It’s caused by a genetic mutation.

  • How common is lymphangioleiomyomatosis?

    LAM is rare. Estimates are that, worldwide:

    • Sporadic LAM affects between 8,000 and 21,000 people.
    • TSC-LAM affects between 80,000 and 160,000 people.

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