Inflammation of the renal pelvis

Inflammation of the renal pelvis, also known as pyelonephritis, is a common condition that occurs when the ureter and kidney become inflamed. It is usually caused by bacteria in the urine which ascends from an untreated urinary tract infection (UTI) in the bladder. The ascending infection can reach all the way up to your kidneys via your ureters. 

It's important to note that none of these symptoms necessarily mean you indeed have inflammation of the renal pelvis (pyelonephritis). Symptoms may vary and could be indicative of other conditions such as appendicitis or diverticulitis for example.


inflammation of renal pelvis
renal pelvis inflammation


Pyelonephritis is sometimes called 'the sickest patient in the hospital', primarily because of the fever, chills and loss of appetite that is often accompanied by nausea, vomiting, and back pain.


Stages of pyelonephritis

There are typically four different stages in pyelonephritis: 

Prodromal:  This stage manifests with vague symptoms such as malaise or lethargy which can progress into chills, fever, rigors (shaking), myalgia (muscle ache), and generalized fatigue. 

Icteric: At this point, you would be feeling very sick with a high-grade fever above 38 degrees Celsius if not higher. Chills may persist along with nausea, vomiting, and sometimes diarrhea. 

Nephritic: This stage is characterized by an abrupt decrease in urine production known as oliguria. This stage could also present with hypertension, hypotension, and increased heart rate. 

Renal: This is another severe stage that can be life-threatening if not treated properly in time. Patients typically report pain in the abdomen or back, nausea, vomiting, and shivering secondary to cold sweats/rigors.


What are the causes of pyelonephritis?

Pyelonephritis is commonly caused by an ascending infection in the bladder. This most often occurs when bacteria from your own gut colonize your urethra or bladder - this is known as asymptomatic urinary tract infection. Other ways include kidney stones, trauma to the urinary tract, and surgery of course.

It's important to note that pyelonephritis is another potential complication that can arise following ERCP which stands for endoscopic retrograde cholangiopancreatography. 

Typically, in these cases, there are high bacterial counts in bile with pancreatic exsudative diarrhea resulting in its spread across the biliary tree into the kidneys where it causes inflammation of one or both of them leading to pyelonephritis.


What are the symptoms of inflammation of the renal pelvis?

Pyelonephritis usually presents abruptly (acutely) with fever (over 38 degrees Celsius) accompanied by chills, rigors (shaking), myalgia (muscle pain), generalized fatigue, and occasionally nausea and vomiting. Physical exam may reveal an enlarged kidney due to acute inflammation in this area which will feel firm when palpated compared to your other kidney. A tender, enlarged, and warm lower left quadrant of the abdomen (where your kidneys are situated) may indicate possible inflammation of the renal pelvis.

The symptoms may vary depending on individual circumstances so don't be alarmed if you only have a few or none at all. Also bear in mind that these symptoms can be indicative of other conditions such as appendicitis and diverticulitis, for example, so please do see a doctor if you experience any of these symptoms: 

  • Abdominal pain/tenderness; 

  • back pain; blood present in your urine; 

  • burning sensation while urinating; 

  • decreased amount of urine; 

  • frequent need to pee (polyuria); 

  • fever (over 38 degrees Celsius); 

  • nausea/vomiting; 

  • pain during urination; 

  • pain in your side/back;

  • shivering; 

  • stomach ache; 

  • unusual tiredness (fatigue).

You might also experience symptoms that are not specifically related to inflammation of the renal pelvis such as headache, chills, fever, and nausea which may be indicative of sepsis. This is a serious condition due to the presence of bacteria in the blood. It could lead to death if not treated immediately so it's important to seek medical attention urgently if any of these symptoms appear. 

Symptoms can worsen over time so don't delay going to see a doctor because there might be a more severe underlying condition causing them.  See a doctor straight away if you have any of the aforementioned symptoms.


What tests to perform for pyelonephritis?

The first thing a doctor should be doing is getting a clean catch urine sample to look for infection and sugar (sometimes called glucose) in the urine. A CBC count, blood culture, and CMP (comprehensive metabolic panel) can also be used to help diagnose or rule out other conditions that could be causing the symptoms such as appendicitis or diverticulitis. Angle-closure glaucoma, pseudotumor cerebri, and meningitis must also be ruled out as potential causes of your signs/symptoms. 

Depending on how well you respond to initial treatment, imaging studies such as ultrasound and CT scans may be ordered to rule out injury or abnormalities.

In severe cases of pyelonephritis, a kidney biopsy may be necessary to determine the severity and type of infection; this is especially true if your symptoms persisted or failed to improve with antibiotics.


What are the treatment options for pyelonephritis?  

Antibiotics are typically used in milder cases while antimotility agents (antidiarrheals) will be prescribed should your doctor suspect bowel obstruction secondary to inflammation. 

Likewise, diuretics such as furosemide can help flush out excess fluid from your kidneys should you also display signs of congestion like edema (swelling).   

If you're experiencing fevers along with chills and rigors, you'll obviously need to be kept under close observation for shock. 

On the other hand, patients with minimal symptoms may be able to treat themselves at home just as long as they are closely following up with their doctor's visits and antibiotic treatment.


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What are the best foods to eat right after being diagnosed?

Now, this really depends on how advanced your condition is but in general, you should aim to replace lost electrolytes by consuming lots of fruits and vegetables. These include but are not limited to bananas, strawberries, coconut water, etcetera.

People who have obstructed bowels due to blocked bile ducts will absolutely want to avoid eating anything that could worsen their condition like spicy or fried food; caffeinated drinks and alcohol for example also need to be limited. 

Fluid replacement is of paramount importance here so you should drink plenty of water as well as fruit juices especially lemon/lime juice which can help to break down kidney stones (calcium oxalate) that could have built up in your kidneys over time.


What are the foods to avoid?

Typically, it's best to avoid or limit intake of dairy products like milk, cheese, etcetera due to the high amount of calcium they contain. The same goes for other sources of dietary calcium found in nuts and seeds.

Likewise, you'll want to minimize your intake or eliminate these potentially harmful foods from your diet completely: fried food, red meat (especially processed meat like deli meats), soft drinks, alcohol, and caffeine.


What are the best exercises to do?

Typically, you'll want to engage in long walks or light jogs as these exercises will help improve blood circulation and facilitate the removal of waste products such as lactic acid from your kidneys. Swimming is also a very good option especially if you're dealing with an infection that has spread throughout your urinary tract which typically occurs with severe cases of pyelonephritis.


When can I return back to work and normal activities?

This really depends on how bad the condition was and how fast your body was able to recover. For some people, it may take several months while for others it only takes a matter of weeks.


Can you have sex while being treated?

Yes, but both you and your partner will need to use condoms or refrain from intercourse entirely until all signs of the infection are gone. You should also limit sexual activity to light foreplay until you've taken a follow-up test that proves negative for any STIs.