Hereditary transthyretin (hATTR) amyloidosis is a rare disease caused by misfolded transthyretin (TTR) proteins. When the transthyretin protein becomes deformed and doesn’t take on its proper shape, it is known as misfolding. These abnormal proteins clump together to make fibrils that become stuck in organs throughout the body, causing several different symptoms. Depending on which parts of the body are affected, you may notice one or more sets of symptoms that can make diagnosing the disease difficult.

These symptoms may show up in different ways at different times, or they may change or get worse as the disease progresses. It can take several years for enough amyloid fibrils to build up to cause noticeable symptoms.

In this article, we’ll discuss seven symptoms of hATTR amyloidosis to watch out for. Because this condition can affect your entire body, it’s essential to be aware of which symptoms are connected. Knowing these signs can prompt you to visit your doctor sooner rather than later so you can start treatment as quickly as possible.

1. Numbness or Tingling in Your Hands and Feet

Your nervous system is made of millions of delicate nerve cells that can be easily damaged by amyloid fibrils. Often, one of the first noticeable symptoms of hATTR amyloidosis is numbness or tingling in your hands and feet, also known as peripheral neuropathy.

Polyneuropathy is diagnosed when peripheral nerves throughout your body are damaged by the buildup of amyloid protein. Peripheral nerves are a network of nerves that connect the brain and spinal cord (central nervous system) to the rest of the body. As hATTR amyloidosis progresses, nerve damage begins to interfere with your ability to move and perform daily activities. You may lose voluntary control of your muscles, making it more difficult to walk or pick up objects. Some people also lose sensitivity to temperature or become extremely sensitive to pain.

2. Carpal Tunnel Syndrome

Studies have also found that carpal tunnel syndrome (CTS) in both wrists can be an early sign of hATTR amyloidosis. In fact, many people have CTS for years before receiving a diagnosis of hATTR amyloidosis. Amyloid fibrils become stuck in the tendons and tissues, causing inflammation and putting pressure on the nerves.

Symptoms of CTS include:

• Pain or numbness in your hands
• Weak grip when picking up objects
• Numbness, burning, or tingling in your fingers, especially your index and middle fingers and thumb
• Swollen sensation in your fingers

CTS is a common condition affecting 1 to 3 in every 1,000 people in the United States. Typing on a keyboard, hand or wrist injuries, and living with other bone or joint diseases can all cause CTS. If you work an office job or if you have osteoporosis or rheumatoid arthritis, that may be the driving factor behind your CTS rather than amyloidosis.

If you’ve noticed any new hand pain or weakness, especially with other hATTR amyloidosis symptoms, talk to your doctor. CTS can be a painful and difficult condition to live with, so it’s best to seek treatment as soon as possible.

3. Gastrointestinal Issues

Nerve damage caused by hATTR amyloidosis can also affect your autonomic nerves. These nerves are responsible for controlling your body’s automatic functions, including digestion, as well as bladder and bowel functions. Autonomic neuropathy is also an early sign of hATTR amyloidosis, especially when it affects your stomach and intestines.

Gastrointestinal issues associated with hATTR amyloidosis include:

• Severe constipation
• Diarrhea
• Early satiety (feeling full early in a meal)
• Nausea
• Gastroparesis (slowed stomach emptying)

In some people, these problems may lead to weight loss.

4. Dizziness When Standing Up

Have you ever stood up too fast after sitting or lying down and become very dizzy? This is known as orthostatic hypotension, and it affects 40 percent to 60 percent of people with hATTR amyloidosis. Autonomic neuropathy also affects your body’s ability to regulate blood pressure. If your blood pressure drops too low, you may become lightheaded and dizzy — in some cases, you may even faint.

The most common causes of orthostatic hypotension are lying in bed for an extended period of time or dehydration. If neither of these situations applies to you or if you’ve been experiencing dizziness after standing up, and it’s been continuing for weeks to months, it’s a good idea to check in with your doctor.

5. Shortness of Breath and Leg Swelling

Abnormal TTR proteins can collect in your blood vessels and heart, known as cardiac amyloidosis. The buildup of amyloid fibrils can lead to cardiomyopathy, a disease that affects your heart’s ability to pump blood properly. Eventually, this dysfunction leads to congestive heart failure — the heart muscle becomes stiff or enlarged, preventing blood from reaching other parts of your body.

If you have cardiomyopathy or heart failure caused by hATTR amyloidosis, symptoms you may experience include:

• Shortness of breath due to fluid buildup in your lungs, even when sitting or lying down
• Extreme tiredness or fatigue
• Lightheadedness or dizziness
• Edema (swelling in your feet, ankles, and legs)
• Pressure in your chest

If you have a family history of heart disease, or if you have high blood pressure or high cholesterol levels, it may point to a cause other than hATTR amyloidosis. Your doctor will take other symptoms you have into consideration when making a diagnosis.

Read about life expectancy with hATTR amyloidosis.

6. Abnormal Heartbeat

Amyloid deposits in the heart can also interfere with your heart’s electrical system, making your heart beat out of rhythm. Known as an arrhythmia, an abnormal heartbeat may increase your risk of stroke and other health complications. This condition can affect the top chambers of your heart (atria) or the bottom chambers (ventricles), which can cause different symptoms.

Signs that you may have an arrhythmia include:

• Heart palpitations (fast, pounding, or fluttering heartbeat)
• Trouble breathing, especially when sleeping
• Feeling weak or tired
• Chest discomfort or pain
• Anxiety
• Feeling faint or dizzy

7. Vision Problems

While your liver makes most of your body’s TTR protein, the cells in the back of your eye (known as the retina) make some as well. Around 10 percent of people with hATTR amyloidosis have vision problems and other symptoms associated with the production of abnormal TTR proteins in the eyes. These symptoms tend to develop later in the disease after it’s progressed.

Vision and eye problems that develop in hATTR amyloidosis include:

• Floaters, or dark spots or strings in your vision that suddenly move when you try to focus on them
• Changes in your pupils (the dark center of your eyes)
• Enlarged or abnormal blood vessels on the conjunctiva (the outer layer of your eyes)
• Glaucoma, which causes increased blood pressure within your eyes

Vision issues such as glaucoma are more common among older individuals, those living with diabetes, individuals with high blood pressure, and those who have experienced eye injuries.

Your eye doctor will discuss your risk factors with you and perform an eye exam to find the cause.

The symptoms mentioned in this article can be similar to those of other conditions, so a proper diagnosis from a health care professional is necessary. Early detection and starting effective therapies can help manage symptoms and improve the quality of life for individuals with hATTR amyloidosis.

Talk With Others Who Understand

MyAmyloidosisTeam is the social media network for people with amyloidosis and their loved ones. Members come together to ask questions, give advice, and share their experiences with others who understand life with amyloidosis.

Which symptoms of hATTR amyloidosis have you experienced? Leave a note in the comments below, or start a conversation by posting on your Activities page.