A kidney is a bean-shaped organ that filters waste and extra water from the body to make urine. Typically, humans have two kidneys. Kidneys are about the size of a fist and located beneath the ribcage toward the back of the body — one to the left of the spine and one to the right of the spine. Kidney cysts occur when a fluid-filled sac, or sacs, form within kidney tissue. Kidney cysts are usually caused by polycystic kidney disease (PKD) or acquired cystic kidney disease (ACKD).
Polycystic kidney disease runs in families, and the cysts replace healthy kidney tissue. The cysts enlarge the kidneys and prevent them from working properly, which can lead to kidney failure. Cysts can also occur in other organs and parts of the body. In the United States, about 600,000 people have polycystic kidney disease. There is currently no cure for PKD, but treatment is available to help manage symptoms and slow the progression of kidney disease.
Acquired cystic kidney disease usually happens in people who are on kidney dialysis. People who have ACKD have no change in the size of their kidneys, and cysts don’t form in other parts of the body. About 90% of people who have been on kidney dialysis for five or more years develop ACKD. ACKD often has no symptoms and, in most cases, the cysts are harmless and don’t need treatment.
Kidney cyst causes
Polycystic kidney disease
Polycystic kidney disease is a genetic disorder. People who have PKD are born with a gene that causes the disease.
Acquired cystic kidney disease
Adults and children who have chronic kidney disease or end-stage kidney disease can develop acquired cystic kidney disease. People who are on kidney dialysis are more likely to develop ACKD, and the chances of developing ACKD increase the longer someone is on dialysis.
Kidney cyst symptoms
Polycystic kidney disease
People who have polycystic kidney disease are born with a gene that causes the disorder. However, PKD symptoms do not typically develop until someone is 30 to 40 years old. Symptoms of PKD include:
- High blood pressure, sometimes presenting as headache
- Enlarged abdomen
- Back or side pain
- Regular bladder or kidney infections
- Blood in the urine
- Fluttering or pounding in the chest
Acquired cystic kidney disease
People who have acquired cystic kidney disease typically don’t have any symptoms. Complications from acquired kidney disease, like an infected cyst or tumors in the kidneys, can have signs or symptoms. Problems that can arise from ACKD include:
- Fever or back pain – An infected kidney cyst can cause fever and/or pain at the infection site, typically felt in the lower back.
- Blood in the urine – If a cyst in the kidney is bleeding, the blood can travel into the urine and will be visible when you pee.
- Tumors – People who have ACKD are more likely to develop tumors in the kidneys than people who do not. Early-stage kidney tumors usually do not have any signs, but larger kidney tumors can cause low back pain on one side, blood in the urine, fatigue, fever and weight loss.
Kidney cyst diagnosis
Polycystic kidney disease
The most reliable way to diagnose PKD is through imaging tests. In some cases, genetic testing may be performed. The Ohio State University Wexner Medical Center in Columbus, Ohio, offers the most advanced diagnostic tools for assessing kidney disease. These include:
- Ultrasound
- Computerized tomography (CT) – CT is ideal for detecting smaller cysts that ultrasound could miss.
- Magnetic resonance imaging (MRI) – MRI is also good for detecting smaller cysts that ultrasound could miss.
- Genetic testing – Genetic testing is performed by doing a blood draw and having a lab test the blood for genetic markers. Genetic testing is not recommended for everyone, but it can be useful if a patient has an inconclusive diagnosis based on imaging tests, or has a family history of PKD and wishes to start a family or donate a kidney.
Acquired cystic kidney disease
A doctor can diagnose ACKD by taking a medical history and performing imaging tests.
- Medical history – A doctor will ask you questions about past illnesses, treatments and symptoms. If you have been on dialysis for several years and develop symptoms that could point to complications from ACKD, like blood in the urine or fever, then you may have ACKD.
- Imaging tests – If a doctor suspects you have ACKD, they will order one or more imaging tests to confirm. Imaging tests include ultrasound, CT or MRI. The images are painless and you won’t need to be sedated to have them performed. A radiologist — a doctor who specializes in reading X-rays and medical images — will review the images and either confirm you have ACKD or verify that you don’t have cysts in your kidney tissue.
Kidney cyst treatment
Polycystic kidney disease
There is currently no cure for PKD, but experts at The Ohio State University Wexner Medical Center work with patients to advise them on the best options to manage symptoms and slow the rate of kidney disease. These include:
- Drinking water throughout the day and avoiding caffeine – This can slow the growth of cysts.
- Controlling blood pressure – You can manage your blood pressure through diet, exercise and medication.
- Prompt treatment of a bladder or kidney infection – Quickly treating a bladder or kidney infection with antibiotics can help keep kidneys working properly.
- Making healthy lifestyle choices – Regular exercise, a healthy diet and refraining from unhealthy habits like smoking can help keep your kidneys functioning their best.
Acquired cystic kidney disease
If you’re not having any complications from ACKD, treatment isn’t needed. If you’re experiencing symptoms from problems caused by ACKD, treatments are available. Issues that can arise from ACKD that may require treatment include:
- Infected cyst – Your doctor can prescribe an antibiotic, which is medicine that kills bacteria.
- Painful/enlarged cyst – Your doctor can drain a cyst by inserting a long needle through the skin.
- Tumor – A surgeon can remove kidney tumors if they pose a serious threat to your health.
If you have ACKD, you should undergo regular screenings by a health care provider to check for cyst or tumor growth. Speak with your doctor about setting up a screening schedule.
Learn more about kidney care at Ohio State.