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What is an Enlarged Kidney?

An enlarged kidney, medically known as hydronephrosis, occurs when urine builds up within one or both kidneys, causing swelling. This condition can stem from various underlying issues, such as blockages or reflux, and may lead to discomfort or serious health complications. Intrigued by how this condition affects the body? Discover the signs, causes, and treatments as we explore the impact of an enlarged kidney.
Nat Robinson
Nat Robinson

An enlarged kidney is a condition in which a kidney is larger than its normal size. Generally, kidney enlargement is a symptom of an underlying disease or disorder of the kidneys. Some common illnesses that may cause this to occur include polycystic kidney syndrome, a kidney stone and unilateral hydronephrosis. Most of the time, the enlarged kidney is treated by treating the underlying cause of this condition.

The kidneys are vital to human survival. Most people are born with two of these bean shaped organs, which are located in the middle portion of the back. Kidneys function by removing excessive water and waste from the bloodstream. This waste eventually becomes urine, which is passed through tubes, known as ureters, into the bladder where it is eventually released from the body.

A doctor who specializes in kidney functions is a nephrologist.
A doctor who specializes in kidney functions is a nephrologist.

Polycystic kidney syndrome is a condition in which multiple cysts grow within the kidneys. The water-filled cysts are typically benign or noncancerous growths that can vary in size. An enlarged kidney is generally a symptom of this syndrome, as the cysts will cause the kidneys to expand. Other common symptoms may include abdominal swelling, back pain, headache, frequent urination and high blood pressure. If left untreated, high blood pressure can lead to other serious health problems, such as stroke, heart attack and kidney failure.

Polycystic kidney disease can cause an enlarged kidney.
Polycystic kidney disease can cause an enlarged kidney.

A kidney stone is a hard deposit of minerals and salt that form inside the kidney. Commonly, stones form as minerals in urine crystallize and attach to each other. The development of stones inside the kidneys can cause them to grow, leading to an enlarged kidney. Kidney stones can grow quite large. An individual with this condition may experience frequent and painful urination, nausea, fever and pain in the back, abdomen or sides.

Kidney stones may cause an enlarged kidney.
Kidney stones may cause an enlarged kidney.

Unilateral hydronephrosis refers to one enlarged kidney that is swollen due to backed up urine. If both kidneys are swollen the condition is known as bilateral hydronephrosis. Generally, these conditions occur as a result of another problem with the kidneys which prevents urine from entering into the bladder and therefore backing up in the kidneys. An obstruction can be a possible reason for this occurrence. For this reason, in addition to kidney enlargement, an abdominal mass can sometimes be present in an individual with this condition.

In some cases, both kidneys can become enlarged.
In some cases, both kidneys can become enlarged.

If a doctor suspects a patient to have an enlarged kidney, he or she will generally refer the patient to a doctor specializing in nephrology, the study of kidney diseases and treatments, or urology, the study of diseases and treatments of the urinary tract of all people and reproductive organs in men. The doctor will typically send the patient for a medical diagnostic test to pinpoint the cause of the enlarged kidney, so a treatment plan can be made. Any symptoms of a problem with the kidneys should be investigated by a health care professional at once, as untreated problems could lead to the kidneys becoming damaged or failing to function all together.

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Discussion Comments

I found out at age 26 that I had polycystic kidney disease. I enrolled in a clinical trial for a drug to treat the condition, and I am happy to report that they have found that it works! It shrinks kidney volume by 50% by shrinking the cysts.

However, there were major side effects to the drug. I stopped taking it after three days because of them.

It is a powerful diuretic, so it makes you pee a lot. Also, it makes you so thirsty! I drank twenty 11 ounce bottles of water the first day I was on the medication.

It made my blood pressure shoot up, so I had to stop taking it. However, all the other participants continued taking it, and the wonderful results were published after the trial.


Aren't enlarged kidneys in adults frequently associated with high blood pressure? It seems that I remember hearing that enlarged hearts indicate heart problems, and enlarged kidneys are related to this somehow.


@sunshined – That is so true! I have a friend who frequently gets severe kidney stones and enlarged kidneys, and she only drinks soda and tea. She never drinks water.

Even though the doctor told her that switching to water or at least drinking it more than soda or tea could help prevent the stones from coming back, she continues to stick to her habit. I don't see how she does it!

Water flushes out toxins in your kidneys. Also, cranberry juice is very good for kidney health. It can help prevent a kidney infection if you drink it regularly.


@honeybees – I know what you mean! I was having severe pain around my belly button area, and it turned out to be due to enlarged kidneys.

I had a CT scan, because the doctor thought it was a gastrointestinal issue. That's when she saw the kidney cysts and diagnosed me with polycystic kidney disease.

I have to have an ultrasound every three years now, because with this disease, there is an increased risk of developing kidney cancer. For me, the ultrasound is painful, because the technician has to push down on the cysts, and sometimes, they rupture.


I went to the doctor for pains and found out that I had a cyst on my left ovary, gallstones and an enlarged kidney on my right side. I think I still have them because I still get the pains, but not as bad as they were then.


It is interesting that although your kidneys are located in your back, that often times your pain will be in your sides or stomach area. I was having some nagging pain in my left side and my doctor sent me to a specialist who did an enlarged kidney ultrasound.

The ultrasound is not painful at all, and it was worth knowing what was causing the pain. My blood pressure was also quite high, and that is another reason they sent me for the ultrasound because there is a connection between high blood pressure and kidney problems.


If you have kidney stones, or any problems that are similar to enlarged kidney symptoms, one of the best things any one can do is to drink lots of water.

Most people don't get the recommended 8 glasses a day anyway, but this is really important when you are trying to clean and detoxify your kidneys.

You will probably be running to the bathroom all the time at first, but won't have to as much once your body gets adjusted to it.


I was having a lot of pain in my right side and when I went to the doctor found out that I had an enlarged right kidney and kidney stones. I had never had this before, and it is very painful.

The kidney stones did eventually pass, but that is something I do not want to go through again. My doctor told me to stop drinking as much soda. I have a bad habit of drinking too much soda, so that helped me cut back quite a bit.

I have not have any problems since, but will know what it is if I start having symptoms again.


i just found out that i have an enlarged kidney and liquid in the kidney and they said it was on my left side but it hurt me on my right side.

the pain comes from my back to my front all the way to bottom of my belly button. it is very painful and sometimes i feel cramping in the front and back. what can i do to make it better? Thank you.

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    • A doctor who specializes in kidney functions is a nephrologist.
      By: Monkey Business
      A doctor who specializes in kidney functions is a nephrologist.
    • Polycystic kidney disease can cause an enlarged kidney.
      By: Alila
      Polycystic kidney disease can cause an enlarged kidney.
    • Kidney stones may cause an enlarged kidney.
      By: Alila Medical Media
      Kidney stones may cause an enlarged kidney.
    • In some cases, both kidneys can become enlarged.
      In some cases, both kidneys can become enlarged.
    • A urinalysis may be conducted to detect kidney stones, which can cause the kidney to become enlarged.
      By: Mi.Ti.
      A urinalysis may be conducted to detect kidney stones, which can cause the kidney to become enlarged.