Polycystic Kidney Disease: Symptoms, Causes, And Treatment Options

The kidneys play a vital role in the body. They maintain the proper levels of electrolytes, control your body's fluid balance, and remove waste in the form of urine. However, when the organs are affected by kidney disease, they cannot filter excess water from your blood, waste, and toxins.

Polycystic kidney disease can affect the ability of your kidneys to clear waste to maintain an overall fluid balance in your body. It's not uncommon for people to be affected by polycystic kidney disease¹ and be unaware until a later stage. 

What is polycystic kidney disease?

Polycystic kidney disease (PKD) is a chronic kidney disease² brought about by a genetic disorder that causes the growth of cysts in the kidneys, resulting in disrupted normal function. Cysts are the abnormal growth of non-cancerous sacs filled with liquid, gas, or semi-solid substances.

The cysts can change the shape of the kidneys, making them larger. Polycystic kidney disease differs from simple kidney cysts. Simple kidney cysts³ rarely cause complications — if they lack symptoms, they don't require treatment and can disappear independently.

There are two types of kidney disease:

• Autosomal dominant polycystic kidney disease (ADPKD)

ADPKD is the most common type of polycystic kidney disease. It is often diagnosed in adulthood, between 30-50 years. However, it can also occur in early childhood or adolescence.

• Autosomal recessive polycystic kidney disease (ARPKD)

Also known as infantile polycystic kidney disease. This is a rare form of polycystic kidney disease. It causes abnormal kidney development while the child is in the womb or soon after birth.

In addition, polycystic kidney disease can cause cysts to grow in other organs in your body like the liver, spleen, pancreas, ovaries, heart, and brain. The cysts in most of these organs don't usually cause many problems, but if they affect your brain, they can cause an aneurysm — a bulging blood vessel.

An aneurysm can burst anytime as it often lacks symptoms, resulting in stroke or death. In addition, if polycystic kidney disease affects your heart, it can cause the valves to become floppy, bringing about a heart murmur in some people.

Symptoms of polycystic kidney disease

Most people with polycystic kidney disease do not develop notable symptoms until they are 30-50 years old unless it occurs early in life or is autosomal recessive polycystic kidney disease⁴ (ARPKD). Polycystic kidney disease symptoms include:

• High blood pressure

• Side or back pain

• Bloody urine (hematuria)

• Feeling bloated or full in the abdomen

• Headaches

• Larger abdomen due to enlarged kidneys

• Urinary tract or kidney infection

• Kidney stones

• Pounding or fluttering sound in the chest

• Kidney failure

Causes of polycystic kidney disease

The leading cause of polycystic kidney disease is gene mutation — when a child inherits the mutated gene from their parent. Mutations in the specific genes polycystin-1 (PKD1) and polycystin-2 (PKD2) cause autosomal dominant polycystic kidney disease, while fibrocystin (PKHD1) causes autosomal recessive polycystic kidney disease. 

These genes are responsible for providing instructions in making proteins. So, when the gene mutates, the message is altered, leading to the formation of multiple cysts in the kidney.

Most people, at least 90% with polycystic kidney disease, have an autosomal dominant pattern of inheritance, where one is born with one mutated copy of PKD1 or PKD2 in each cell.

The growth rate of the cysts depends on the number of inherited mutated gene copies of PKD1 or PKD2. Parents of an infant with autosomal recessive polycystic kidney disease are not affected but carry a copy of the altered PKHD1 gene. 

In a small number of polycystic kidney disease cases, the gene mutates independently, without either parent having a copy of the mutated gene. In this case, the kidney disease is called acquired polycystic kidney disease.⁵ Acquired polycystic kidney disease often occurs in people on kidney dialysis due to chronic kidney disease or end-stage kidney failure. 

Complications of polycystic kidney disease

Polycystic kidney disease can result in serious health complications for babies and adults. Adults may have:

• Brain aneurysm

• Chronic pain

• Heart valve problems

• Pancreatic or liver cysts

• Kidney failure

• Kidney stones

• Preeclampsia (high blood pressure during pregnancy)

• High blood pressure

• Colon problems

• Urinary tract infections

Babies may develop:

• Liver problems

• High blood pressure

• Respiratory problems due to underdeveloped lungs

• Kidney failure

How common is polycystic kidney disease?

Polycystic kidney disease occurs in women and men, affecting people of all races, ethnicities, and ages. According to the National Institute of Diabetes and Digestive and Kidney Diseases, polycystic kidney disease affects almost 500,000 Americans⁶ in the US, while ADPKD affects one in every 400-1,000 people, and ARPKD affects at least one in every 20,000 children worldwide. 

In addition, according to the National Kidney Foundation, 5% of all kidney failure⁷ results from polycystic kidney disease.

How is polycystic kidney disease diagnosed?

For polycystic kidney diagnosis, several tests can detect the size and number of kidney cysts to help the nephrologist (kidney health specialist) evaluate the number of healthy tissues available. The kidney health specialist can perform the following tests to diagnose polycystic kidney disease.

Ultrasound

Ultrasound is a non-invasive and reliable way for the doctor to determine if you have the disease. During your appointment, the nephrologist will place a transducer— a wand-like device — on your body. It will emit sound waves, which will reflect back to the device, and the computer will translate the reflected sound waves into images.

CT scan

A computed tomography (CT) scan detects smaller cysts not seen through an ultrasound. You will lie on a big donut-shaped device — a movable table that will project thin X-ray beams through your body  — and the doctor will see the cross-sectional views of your kidneys.

MRI scan

A magnetic resonance imaging (MRI) scan measures the kidney cysts' volume and growth through a large cylindrical machine. It generates radio waves and magnetic fields to provide cross-sectional views of your kidneys.

Sometimes, the nephrologist can request genetic testing to check for abnormal genes in the blood that cause polycystic kidney disease. However, genetic testing can fail to detect the disorder in 15% of people with the disease.

Although it's not recommended for everyone, it's suitable when a person:

• Wants to donate a kidney and has a family history of polycystic kidney disease

• Is under 30 years, has a family history of PKD, received a negative ultrasound result, and wants to start a family

• Have uncertainties based on the imaging tests

Treatment for polycystic kidney disease

The extremity of polycystic kidney disease varies from person to person — even among family members. People with polycystic kidney disease can reach end-stage kidney disease by age 55-65. On the other hand, some may experience a milder version of it and not progress to end-stage kidney disease. 

Polycystic kidney disease treatment involves managing the complications, signs, and symptoms of PKD. Treatment options vary depending on the symptoms. Unfortunately, there is currently no cure for the disease.

1. Kidney cysts growth

A nephrologist can recommend Tolvaptan therapy⁸ for adults at risk of rapidly progressing autosomal dominant polycystic kidney disease (ADPKD). Tolvaptan is an oral pill that slows the growth rate of kidney cysts, helping protect your kidney's function and delaying the need for dialysis or transplant.

Tolvaptan therapy has an increased risk of severe liver injury and can interact with other medications. It can also make you urinate copiously, and you may be instructed to drink up to 4L a day to compensate for this. So, when taking the pill, visit your doctor for close monitoring for complications and side effects. 

2. Declining kidney function

A kidney health expert may recommend maintaining a healthy body weight to help your kidneys stay well for longer. You can achieve this through a low-salt, low-fat diet, and high water intake to slow down the decline in kidney function.

3. Kidney or bladder infection

Treating a urinary tract infection can help prevent further kidney damage. The doctor will examine you for the type of infection to administer suitable antibiotics which will not cause further damage to the kidneys.

4. High blood pressure

Medications known as angiotensin II receptor blockers⁹ (ARBs) or angiotensin-converting enzymes¹⁰ (ACE) inhibitors help control high blood pressure, which delays the progression of the disease. In addition to the medications, having a healthy balanced diet and more active hours may help control your blood pressure.

5. Pain

Over-the-counter medications containing acetaminophen may help you control the pain caused by polycystic kidney disease. However, if the pain is unbearable, the doctor may recommend shrinking your kidneys using a needle to draw out cyst fluid and inject the medicine.

If the cysts are too large, causing pain and pressure, you may need surgery to remove them.

6. Kidney transplant

If your kidneys stop working, the next step is likely to be dialysis or a kidney transplant. This will help return your kidney function to near normal levels but will require intense immunosuppression.

A kidney transplant will not resolve any cysts in other organs (e.g., liver cysts or brain aneurysms).

Is polycystic kidney disease preventable?

Polycystic kidney disease is not preventable but is manageable through treatment options and lifestyle changes. This will slow down the progression of further kidney damage, preventing kidney failure. 

To bearably live with the disorder, consider

• Exercising

• Quitting smoking

• Reducing stress

• Eating a healthy diet — strict salt restrictions and hydration has been shown to help slow the disease.

• Staying within a healthy BMI

• Managing blood pressure

When to call a doctor

If you have a first-degree relative with a polycystic kidney condition, consider booking an appointment with your doctor to discuss the screening of the disorder. However, if you already know you have the disease, contact a healthcare provider if you:

• Are unable to urinate

• Cannot breathe

• Have chest pains 

• Develop swollen feet, legs, and ankles

• Experience recurrent headaches, dizziness, or confusion 

The lowdown

Polycystic kidney disease (PKD) is the fourth leading cause of kidney failure among people with kidney disease. It's essential to visit a health care center if you have a family history of the disorder or have kidney disease. An early diagnosis will ensure that you receive treatment to prevent further damage to your kidneys.