Over time, transthyretin amyloidosis (ATTR) can damage the nerves, heart, and other organs. This may lead to complications like heart problems, nerve damage, and trouble with everyday bodily functions.

ATTR develops when a mutation in the transthyretin (TTR) gene causes your liver to produce abnormal TTR proteins. These proteins clump together into amyloid fibrils, which build up in organs and cause tissue damage.

The buildup of amyloid fibrils may lead to complications that affect your:

  • heart
  • nervous system
  • gastrointestinal system
  • musculoskeletal system
  • kidneys
  • eyes

Symptoms and complications of ATTR usually worsen over time. They can affect your physical health, emotional well-being, and ability to do everyday activities.

Treatment is available to slow the development of ATTR, which may delay or prevent potential complications. This may help improve your quality of life and survival.

Treatments are also available to manage specific complications. Your doctor may recommend direct treatment or refer you to a specialist.

Read on to learn more about potential complications of ATTR.

Amyloid fibrils may build up in your heart muscle and cause cardiomyopathy, or heart muscle disease. This may lead to cardiac complications, such as:

  • heart failure, which happens when your heart can’t pump blood well enough
  • cardiac arrhythmia, or abnormal heart rhythm
  • intracardiac thrombus, or a blood clot in the heart muscle

Atrial fibrillation is one of the most common types of arrhythmias in people with ATTR cardiomyopathy. It’s especially common in wild-type ATTR-CM, but it can also occur in hereditary ATTR (hATTR). Atrial fibrillation raises your risk of stroke.

Your doctor may refer you to a heart specialist (cardiologist) to check for signs of cardiomyopathy and other heart changes. They might order regular heart tests to monitor your heart health and recommend lifestyle changes or treatments to help manage complications.

Amyloid fibrils may build up in the nervous system and cause complications, such as sensorimotor neuropathy and autonomic dysfunction. Your doctor may refer you to a nerve system specialist (neurologist) to diagnose and manage these conditions.

Sensorimotor neuropathy

Sensorimotor neuropathy happens when nerves that control sensation and movement are damaged. It may cause symptoms in your feet, hands, or other body parts, such as.

  • numbness, tingling, pain, or other unusual sensations
  • changes in your ability to feel temperature
  • changes in your sense of touch
  • muscle weakness
  • loss of dexterity
  • lack of balance
  • foot drop, or difficulty flexing your foot up
  • wrist drop, or difficulty extending your wrist and fingers straight

Sensorimotor neuropathy may limit your ability to do certain movements or activities, such as walking. It can also cause challenges with mobility and daily living.

Autonomic dysfunction

Autonomic dysfunction occurs when amyloid buildup damages the autonomic nervous system, which controls involuntary functions such as blood pressure, digestion, and sexual arousal.

Potential symptoms include:

  • lightheadedness, dizziness, or fainting
  • challenges emptying or controlling your bladder
  • diarrhea, constipation, or other bowel changes
  • difficulty tolerating heat
  • unusual sweating
  • hair loss
  • blurred vision
  • dry eyes
  • dry mouth
  • erectile dysfunction

Autonomic dysfunction can also cause orthostatic hypotension, a drop in blood pressure when you sit up or stand up. This raises the risk of falls and accidental injuries.

Nerve damage from ATTR may affect your digestion and bowel movements. Amyloid fibrils can also build up in tissues in your digestive tract.

This may lead to gastrointestinal complications, such as:

  • gastroparesis, or delayed movement of food from your stomach to your intestines
  • dysphagia, or difficulty swallowing
  • chronic constipation or diarrhea
  • malnutrition

These complications can cause symptoms such as:

  • changes in bowel movements
  • changes in appetite
  • unexplained weight loss
  • abdominal pain or swelling
  • feeling unusually full
  • gas (flatulence)
  • nausea or vomiting

Because these symptoms often overlap with other digestive conditions, doctors may sometimes misdiagnose ATTR-related bowel changes as irritable bowel syndrome (IBS). Let your doctor know if you’ve had a past diagnosis of IBS so they can consider ATTR in your care.

ATTR can cause changes in the soft tissues or bones that increase your risk of conditions such as:

  • carpal tunnel syndrome, caused by pressure on the median nerve that runs from your forearm to your palm
  • spinal stenosis, which happens when hollow spaces or openings in your spinal vertebrae narrow and put pressure on your spinal cord or nerve roots
  • rotator cuff injury, involving damage to muscles or tendons that stabilize your shoulder joint
  • tendon ruptures, which are tears

These complications can lead to pain and discomfort. They may also limit your mobility and ability to perform certain activities.

Your doctor may recommend activity modifications, physical therapy, or other treatments to help manage these complications.

Amyloid fibrils may build up in your kidneys and increase the risk of kidney failure, which happens when one or both kidneys can’t filter blood well enough to remove toxins and excess fluid. Kidney failure can also make heart failure worse.

Potential symptoms of kidney failure include:

  • swelling in your feet, ankles, or legs
  • changes in urination
  • fatigue or tiredness
  • difficulty sleeping
  • muscle cramps or weakness
  • joint pain or stiffness
  • dry, itchy skin
  • nausea or vomiting
  • loss of appetite
  • difficulty focusing, memory challenges, or confusion

Your doctor may order routine kidney tests to monitor your kidney health.

They may refer you to a kidney specialist (nephrologist) if you develop signs or symptoms of kidney disease. A nephrologist can help you understand your treatment options.

Amyloid fibrils may build up in the eyes and cause vitreous opacities, which are clumps in the gel-like fluid that fills the eyeball (vitreous humor). These opacities may appear as floaters that drift across your vision.

ATTR can also damage the nerves that affect your eyes, leading to symptoms such as blurred vision or dry eyes.

Regular checkups with an eye specialist (ophthalmologist) are important for diagnosing and managing changes in your vision or overall eye health.

Living with ATTR can bring challenges that affect more than your physical health. People with ATTR often report concerns related to:

  • symptoms and complications
  • changes to their physical abilities or independence
  • changes to their work attendance or productivity
  • the time and cost of getting a diagnosis and treatment
  • how the condition may affect loved ones

These challenges may lead to emotional distress and affect mental health or emotional well-being.

Talk with your doctor about how ATTR is affecting you, especially if you’re experiencing frequent or severe stress, anxiety, or other mental health challenges.

They may refer you to a mental health professional who can share strategies and resources to manage stress and other difficult emotions. Treatment may also be recommended if you show signs of a mental health condition, such as depression or anxiety.

Joining a support group for people with ATTR can also provide understanding, encouragement, and connection.

ATTR can affect multiple organs and lead to complications such as:

  • heart disease
  • nerve damage
  • digestive problems
  • spine, joint, or tendon injuries
  • kidney failure
  • eye changes

Treatment can help slow the buildup of amyloid fibrils, which may delay or reduce complications. Options are also available to help manage complications if they occur. Your outlook will depend on the specific complication and your treatment plan.

Let your doctor know if you develop new or worsening symptoms. Talk with them about changes in your physical health, mental health, and emotional well-being. They may recommend treatment or refer you to a specialist for support.

Joining a support group may also provide encouragement and connection. Taking steps to limit and treat complications can help improve your quality of life.