Kidney Cyst Symptoms, Causes, and Treatments

Understanding Kidney Cysts: Symptoms, Causes, and Treatment Options

Kidney cysts are fluid-filled sacs that form on or within the kidneys, and they are an incredibly common finding, especially as we age. In fact, nearly half of all individuals over 50 will develop at least one simple kidney cyst.

While often harmless and symptom-free, it is important to understand the different types of cysts, such as the common renal cortical cyst. This article provides a comprehensive overview of kidney cysts, exploring their potential symptoms, underlying causes, and the various treatment paths available.

Keep reading to learn how to distinguish between a simple cyst and a more serious condition.

What is Cyst in Kidney?

Kidney cysts are small, fluid-filled sacs that form on or within the kidneys. They are incredibly common, especially as people age, and the vast majority are simple kidney cysts that are non-cancerous and cause no symptoms.

Most people live their entire lives without ever knowing they have a kidney cyst. However, treatment may be recommended if a cyst grows large, becomes painful, shows signs of infection, or is diagnosed as a complex cyst. If you're experiencing symptoms like back pain or fever, it's important to consult a healthcare provider for an accurate diagnosis.

What are the types of Kidney Cyst?

When diagnosed with a kidney cyst, it is crucial to understand which type you have, as their implications for your health vary greatly. Kidney cysts are primarily categorised as simple or complex, but there are also specific genetic and acquired conditions defined by cyst growth.

Here is a breakdown of the main types of kidney cysts.

1.  Simple Kidney Cyst

Simple kidney cysts are the most common type. These are benign, fluid-filled sacs with thin walls that form on the kidneys.

• Characteristics: They are typically round, smooth, and do not cause damage to the kidney tissue.
• Prevalence: They are very common, especially as people age, and are often discovered incidentally during an imaging scan for another issue.
• Symptoms & Risks: Most simple cysts are asymptomatic (cause no symptoms) and are not linked to kidney disease. Treatment is only considered if they grow large enough to cause pain, become infected, or block urine flow.
   

2. Polycystic Kidney Disease (PKD)

PKD is a hereditary condition that tends to run in the family and is not a single cyst but a genetic, or inherited, disorder that causes numerous cysts to develop within the kidneys.

• Characteristics: These cysts can multiply and grow over time, causing the kidneys to enlarge and lose
• Health Impact: PKD is a serious condition that can lead to complications like high blood pressure, kidney infections, and ultimately, kidney failure.
• Other Effects: Cysts may also develop in other organs, such as the liver.
   

Acquired Cystic Kidney Disease (ACKD)

Unlike PKD, Acquired Cystic Kidney Disease (ACKD) is not inherited. It develops in individuals who have long-term kidney damage, particularly those with chronic kidney disease or end-stage renal disease who are on dialysis.

• Cause: ACKD is a result of the underlying kidney dysfunction, not a cause of it.
• Key Difference: While the kidneys develop many cysts, they typically do not grow as large as in PKD. ACKD often does not cause symptoms, but in some cases, cysts can bleed or become cancerous.

Cortical Cyst: The term "cortical cyst" is often used to describe a simple cyst's location. A cortical cyst is simply one that forms in the renal cortex, the outer layer of the kidney. The vast majority of these are benign simple cysts. While they can occasionally cause issues like bleeding or infection, this is rare.

Also Read: Kidney Infection Symptoms 

Other Types of Genetic and Non-Genetic Kidney Cysts

Here is a list of some other types of genetic and nongenetic kidney cysts that also affect common people: 

Glomerulocystic Kidney Disease

This kind of kidney disease is caused by the enlargement of cysts. These cysts create a gap near the region of a person's urinary tract. It is a very rare form of cyst but does affect both infants and adults.

Nephronophthisis

Unlike cortical cysts in the kidney, these cysts occur in the inner part of the kidneys and lead to scarring and inflammation of tubes, which play the role of filtering kidney waste. 

Medullary Sponge Kidney

The Medullary Sponge kidney cysts occur in the innermost part of a person's kidney and block the tubes which function in filtering waste. They are very rare. 

Medullary Cystic Kidney Disease

This type of kidney cyst occurs in the inner part of the kidneys. They lead to inflammation and scarring of tubes, which work on filtering our kidney waste.

Acquired Cystic Kidney Disease

In this condition, the cysts develop over a period of time and lead to the failure of the kidneys. In the more rare cases, cysts could turn cancerous. 

Multi-cystic Dysplastic Kidney

It is one of the more common conditions that affect one or two kidneys and do not develop properly in the region of the uterus. These kinds of cysts replace the normal tissue of kidneys. 

Kidney Cyst Causes

There are a number of theories proposed by doctors on how a simple kidney cyst develops. For instance, approximately a million tiny tubules are used to collect urine in each kidney. It is probable that a tube is blocked, possibly the swelling cause and being filled with fluid, leading to the growth of cysts. Another theory is that the pouches form diverticula in weakened parts of the tubes and fill with fluid.

You're more likely to have cysts in your kidneys as you get older. In the majority of cases, men are at greater risk than women of developing kidney cysts.

The causes of kidney cysts vary significantly depending on the type. For common, simple kidney cysts, the exact cause is not definitively known, but prevailing theories suggest they develop with age due to blockages or weaknesses in the tiny tubules that collect urine within the kidney. One theory proposes that a blocked tubule swells with fluid, while another suggests that pouches, known as diverticula, form in weakened areas of the tubules and fill with fluid. The risk of developing these simple cysts increases with age, and men are generally at a higher risk than women.

In stark contrast, Polycystic Kidney Disease (PKD) is not an age-related development but an inherited genetic disorder. PKD is caused by specific gene mutations passed down through families, which program the kidneys to form numerous cysts that can ultimately impair kidney function.

Also Read: Kidney Stone Types Causes Symptoms

Factors That Increase Risk of Kidney Cysts

Here is a list of some factors which increase the risk of getting cortical cyst in kidney, along with other types as well: 

Role of Genetics

Genetics actually play a very important role in the development of kidney cysts. The most common type of kidney cyst, ADPKD (Autosomal Dominant Polycystic Kidney Disease), is caused by genetic mutations. 

Underlying Health Conditions

Kidney Cysts can also occur as a result of other underlying health conditions like - high blood pressure, chronic kidney disease, diabetes, etc. 

Age of a Person

The age of a person is also a major factor that affects the likelihood of developing kidney cysts. For instance, people over the age of 50 are more likely to get kidney cysts. 

Gender

Men are more likely to get kidney cysts than women, as the occurrence of simple kidney cysts is more common in men. This also increases with age.

Kidney Cyst Symptoms

Kidney cysts are fluid-filled sacs that can form on or within the kidneys. Their symptoms vary significantly depending on whether they are simple kidney cysts or part of a genetic condition like Polycystic Kidney Disease (PKD). In most cases, doctors diagnose them while carrying out other tests related to health problems that become known in the life of an individual, for example, through ultrasound or computerized tomography (CT Scan).

Simple Kidney Cysts

In most cases, simple kidney cysts are harmless and do not cause any symptoms. They are often discovered incidentally during imaging tests like an ultrasound or CT scan performed for other health reasons.

However, if a simple cyst grows large enough or becomes complicated, it may lead to symptoms such as:

• Dull pain in the back, side, or upper abdomen.
• Fever and chills if the cyst become infected.
• Blood in the urine (haematuria).
• Impaired kidney function or a blockage of urine flow (both rare).
• A feeling of fullness or pressure in the abdomen.
   

Note on High Blood Pressure: Some research suggests a potential link between simple kidney cysts and high blood pressure, though the exact nature of this relationship is not yet fully understood.

Polycystic Kidney Disease (PKD)

PKD is a serious inherited disorder that causes numerous cysts to grow in the kidneys. Unlike simple cysts, PKD often leads to noticeable symptoms and can impair kidney function over time. Common signs and symptoms include:

• High blood pressure(a common and often early sign).
• Back or side pain.
• Blood in the urine (haematuria).
• Frequent urinary tract infections (UTIs).
• Headaches.
• A detectable increase in abdomen size due to enlarged kidneys.

Also Read: Kidney Failure Symptoms

Treatment for a kidney cyst depends entirely on its type, size, and whether it is causing symptoms. Many simple kidney cysts require no treatment at all.

When is Treatment Necessary?

Often, a simple kidney cyst discovered incidentally requires no intervention. Your doctor may recommend periodic monitoring with imaging tests to ensure it does not change.

Treatment is typically considered only if a cyst:

• Is large enough to cause pain, discomfort, or pressure on other organs.
• Is blocking the flow of urine or blood within the kidney.
• Shows signs of being infected or bleeding.
• Is suspicious for cancer (though simple cysts are rarely cancerous).

Standard Medical Procedures

For symptomatic simple cysts, the primary treatment options are minimally invasive procedures:

• Aspiration and sclerotherapy: The provider inserts a long, hollow needle through the skin to puncture the cyst and remove fluid. Sometimes, they will also inject a special solution into the cyst to make it less likely to fill up again.
• Surgery: The surgery that is done in the case of cyst removal is usually a laparoscopic surgery. Your healthcare provider inserts thin instruments in the abdomen through small incisions. During surgery, your provider drains the cyst and then cuts or burns away the outer tissue of the cyst.
• Lifestyle Modification: Lifestyle modifications mainly focus on making an affected person lead a healthy weight and reduce their salt intake. They are also required to drink an adequate amount of water every day, along with exercise. Managing diet and blood pressure also becomes necessary to eradicate kidney cysts. 
• Gene Therapy: It is important to clarify that gene therapy for Autosomal Dominant Polycystic Kidney Disease (ADPKD) is purely experimental. It is not an available clinical treatment for simple kidney cysts or for ADPKD at this time. Research is ongoing, but it is not a current therapeutic option.

In summary, for symptomatic simple kidney cysts, treatment is safe and effective, primarily involving sclerotherapy or laparoscopic surgery. Always discuss the most appropriate and evidence-based options with your healthcare provider.

Prevention of Kidney Cysts

When it comes to simple kidney cysts, it is important to understand that there is no known way to prevent them from forming. They are a common part of aging, and their development is not linked to lifestyle choices or diet.

However, you can take proactive steps to support your overall kidney health and reduce the risk of complications from any existing kidney conditions, including cysts.

You can only reduce your risk by:

• Stay Hydrated: Drinking plenty of water helps your kidneys filter waste and may reduce the risk of other kidney issues.
• Limit Sodium Intake: A low-sodium diet helps control blood pressure, a key factor in preserving long-term kidney health.
• Manage Underlying Conditions: Effectively controlling chronic conditions like high blood pressure and diabetes is crucial, as these are leading causes of kidney damage.

Whether it is cortical cyst in kidney or any other type, you need to get it checked immediately. If you are diagnosed with a kidney cyst (whether a cortical cyst or another type), the most important action is to follow up with your healthcare provider. They can determine the type of cyst, recommend any necessary monitoring, and guide you on the best ways to protect your kidney health.

Conclusion

What size of kidney cyst is dangerous? Most simple kidney cysts are benign and do not cause any problems. If a cyst is too large, it can be treated without any significant complications by sclerotherapy or surgery.

Exophytic kidney cyst treatment depends on the size of the cyst and if it is causing symptoms. A cortical cyst in the kidney gets formed in the renal cortex, the outer part of the kidney. Complex kidney cysts are solid, irregularly shaped, or have a thick outer wall.  A 10 cm cyst on kidney is considered large size and needs treatment. Kidney cyst symptoms in females include pain, blood in urine, etc.

Polycystic kidney disease symptoms include headaches, pain in the back and sides, etc. In the case of someone being affected by polycystic kidney disease, it is more serious. Left untreated, PKD can cause severe complications such as hypertension and kidney failure.