Did you know a cyst or a fluid-filled sac can grow in your kidneys also? Learn about how it can affect your kidneys and the causes, symptoms, diagnosis, and treatment of kidney cysts.
A fluid-filled round pouch that grows inside a kidney is called a kidney cyst. Kidneys are the bean-shaped organs that produce urine by clearing out waste from the bloodstream. Single or multiple cysts can be present on a single kidney or both kidneys. Kidney cysts do not usually produce any symptoms and are harmless. As they do not produce any signs or symptoms, they are mostly diagnosed accidentally during an abdominal scan for some other condition. Sometimes, kidney cysts are associated with severe conditions, which can disrupt kidney function.
The two types of kidney cysts are:
1) Simple kidney cysts - These are usually noncancerous, and rarely cause any complications. The cause is still not clear though. Often, a single cyst is seen on the surface of the affected kidney. These cysts do not cause any symptoms and do not require treatment.
2) Polycystic kidney disease - Polycystic kidney disease, otherwise called PKD, is a condition where multiple cysts form on the kidneys. This type of cyst damages the kidney function and structure as they grow larger.
The exact cause of a simple kidney cyst is not known. The kidney has several tiny tubules, which collect urine. Scientists believe the following to be the possible causes of a kidney cyst:
When these tubules get blocked, swell up, or get filled with push, a cyst might start.
When the weakened areas of the tubules form pouches (diverticula), which get filled with fluid and can result in a cyst.
Some of the factors that increase the risk of kidney cysts are:
People older than 50 years. Almost 50 % of people older than 50 years have a kidney cyst.
Men are more susceptible than women.
PKD is an inherited disorder. So it runs in families and results from changes to genes.
The majority of the cysts are very small, which cannot be seen with the naked eye, and you need a microscope to see them. But, some cysts can grow big and can compress the nearby organs and produce symptoms. Symptoms are also seen when the cyst becomes infected. Some of the symptoms of a simple kidney cyst, when it grows too big or gets infected, are:
Dull back pain or between the ribs and pelvis.
The pain becomes severe if the cyst bursts.
Upper abdominal pain.
Blood in the urine.
The symptoms of polycystic kidney disease are:
Back and side pain.
Increased blood pressure.
Blood in the urine.
Asymptomatic cases of kidney cysts that are the cysts that cause no signs or symptoms or do not interfere with the kidney function do not usually need treatment. If you are suffering from any symptoms, the doctor will perform the following tests and procedures to diagnose kidney cysts and to rule out other conditions that result in similar symptoms:
Ultrasound, MRI (magnetic resonance imaging), or CT (computerized tomography) scan - These imaging tests are done to determine if the growth on the kidney is a cyst or a tumor.
Kidney function tests - To check if the growth on your kidney is impairing the functioning of your kidneys.
Urinalysis - The content of the urine is tested.
Asymptomatic cases of kidney cysts, that are the cysts that cause no signs or symptoms or do not interfere with the kidney function, do not usually need treatment. For such cysts, the doctor will suggest you get periodic imaging tests (ultrasound) to check if the kidney cyst is growing. The doctor will recommend treatment if the kidney cyst increases in size or starts producing symptoms. Sometimes, a simple kidney cyst resolves on its own. The treatment for symptomatic kidney cysts include:
Sclerotherapy - The cyst is punctured and drained and then filled with alcohol. The doctor will first inject an anesthetic solution, and then insert a long and thin needle into the cyst wall through the skin with the help of an ultrasound. Then the needle is used to draw out the fluid. The cyst is refilled with alcohol to prevent recurrence.
Surgery - If the cyst is big and affecting kidney function, then the cyst needs to be surgically removed. The cyst is first drained and then removed. The surgeon makes several small cuts in the skin and inserts specialized instruments through the incisions. The instruments have a camera at its end, which helps the surgeon visualize and guide the instruments to drain the fluid that is filled in the cyst. The pouch surrounding the cyst is then burned or cut off.
In rare cases, simple kidney cysts can result in the following possible complications:
The cyst can rupture and cause pain.
The cyst can get infected.
The kidneys get swollen due to urine obstruction.
Blood in the urine.
If you are experiencing these symptoms, then consult a doctor immediately. When treated promptly, most complications are not fatal. But if left untreated, the symptoms worsen and can also be fatal.
Polycystic Kidney Disease (PKD)
It is an inherited condition that results in clusters of cysts within the kidneys. It makes the kidneys to enlarge and loss of kidney function over time. These cysts can vary in size and shape and can even grow very large. The cyst can also grow in the liver or other body organs. PKD can result in high blood pressure and kidney failure. The incidence of complications can be reduced with the help of lifestyle changes and treatments. Most complications are preventable and depend on the severity of the condition.
In general, a simple kidney cyst is usually harmless and does not cause any complications. In case the cyst grows, surgery or sclerotherapy can help prevent permanent kidney damage. For more information on kidney cysts, consult a nephrologist online now!
Last reviewed at:
22 Jan 2020 - 4 min read
Query: Hi doctor, My son is 12 years old. Last week we found out that he has a complex cyst in his kidney. I am so worried and cannot wait until I see a urologist next week. So, I want to show you the ultrasound images and get your opinion on it. The GP said that he has a complex cyst and this scares me ev... Read Full »
Query: Hello doctor, I am a 71-year-old male with h/o HTN and diabetes. They are well under control with Amlopres one tablet daily and Cetaphin 500 mg two tablets daily, Clopitab 75 mg one tablet daily. I have a cyst in my kidney which is asymptotic. Nephrologist did not prescribe any medicine for that. ... Read Full »
Query: Hello doctor, During a health check-up, I got to know that I have a renal cyst on my right kidney. I did a follow-up ultrasound about a month ago and I found that now I have developed a cyst in my left kidney as well over and above the cyst in the right kidney. Which means now I have a cyst in both... Read Full »
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