Interstitial nephritis is a kidney condition characterized by swelling in between the kidney tubules. Symptoms include fatigue, itching, urinary changes, and twitching.
What is interstitial nephritis?
Interstitial nephritis is a that results when the spaces between the kidney tubules become swollen and inflamed. These spaces are also known as the interstitium. The tubules are the structures of the kidney responsible for filtering fluid.
The chronic form of interstitial nephritis seriously affects the way your kidney works. The kidney is responsible for filtering waste and excess fluid from the blood and excreting it into the urine.
Treatments for interstitial nephritis include adjusting troublesome medication, alleviating underlying causes, steroids, and dialysis.
You should go to your primary care physician(PCP) tomorrow for a sick visit.
Symptoms of interstitial nephritis
Signs and symptoms of interstitial nephritis are not always obvious because the damage progresses slowly and over time. Signs and symptoms include:
- Loss of appetite
- Fatigue and weakness
- Sleep issues
- Urinary changes: The frequency and quantity of your urine may change.
- Muscle twitches and cramps: These may occur due to a buildup of electrolytes that the kidney is not able to filter.
- Swelling of feet and ankles (edema): This may occur due to fluid buildup due to the kidneys' inability to properly excrete excess fluid.
Chronic interstitial nephritis can result in complications of other organs and other conditions due to the kidney's importance in maintaining homeostasis (balance) within the body. This can result in the following due to impaired fluid regulation and other functions.
- : If fluid builds up around the lining of the heart (pericarditis).
- : If fluid builds up around the lungs (pulmonary edema).
- High blood pressure: This is due to excess fluid throughout the body in general which the heart has to pump against (hypertension).
- Since the kidney's ability to filter and excrete electrolytes is impaired, a rise in levels of electrolytes such as potassium (hyperkalemia) can result in life-threatening problems.
- Chronic kidney disease: Interstitial nephritis can often affect the kidney to the point where its function is significantly impaired — this condition is known as .
Causes of interstitial nephritis
Anything that causes prolonged inflammation and damage to the spaces surrounding the kidney tubules can result in interstitial nephritis and even chronic kidney disease. The causes of kidney inflammation are varied, but can be divided into the following categories:
- Some medications, particularly certain antibiotics and nonsteroidal inflammatory drugs (NSAIDs) can be particularly toxic and damaging to the kidney. Persistent use of these drugs to treat other conditions can adversely affect the kidney and cause chronic inflammation, leading to chronic interstitial nephritis and chronic kidney disease.
- Infections: Bacteria that invade and infect the kidney cause a type of infection known as pyelonephritis. Pyelonephritis that is not treated or treated improperly can result in chronic inflammation of the kidney interstitium.
- Autoimmune conditions: Many inflammatory diseases that result in the body attacking itself can also affect the kidney and cause injury that results in interstitial nephritis. Conditions such as multiple sclerosis (MS) and lupus (SLE) are examples of such autoimmune diseases.
Treatment options and prevention for interstitial nephritis
Chronic interstitial nephritis does not have a cure. Treatment focuses on addressing and treating the underlying cause of the inflammation, alleviating symptoms, and helping the kidney function as best as possible with medical management. Options for treatment include:
Medication may help alleviate symptoms of interstitial nephritis, in regards to the following.
- Discontinue certain drugs: If the inflammation is caused by a certain drug or class of drugs, your physician will discuss discontinuing the drug and using possible alternatives.
- Steroids: These are often used in the treatment of multiple autoimmune diseases and may alleviate some of the inflammation.
If your kidney function is significantly impaired to the point that it cannot maintain waste and fluid clearance on its own, your physician may suggest Dialysis is a system that artificially removes waste products and extra fluid from your blood when your kidneys can no longer perform this function. There are two types, hemodialysis and peritoneal dialysis:
- Hemodialysis: A machine filters the waste and excess fluids from the blood.
- Peritoneal dialysis: A thin tube (catheter) inserted into your abdomen fills your abdominal cavity with a dialysis solution that absorbs waste and excess fluids and drains them from the body, carrying the waste outside of the body.
Your physician may also suggest this option if your kidney function is significantly impaired. A kidney transplant involves surgically replacing your defective kidney for a healthy kidney from a donor into your body. Transplanted kidneys can come from deceased or living donors. You'll need to take medications for the rest of your life, called immunosuppressants, to keep your body from rejecting the new kidney.
There are many things you can start doing at home to help control and alleviate some of your symptoms. These changes will not cure you of your chronic interstitial nephritis but may help slow the progression of the disease.
- Follow instructions on over-the-counter medications: Since medications are a primary trigger for interstitial nephritis, make sure to follow instructions on nonprescription pain-relievers such as aspirin or ibuprofen (NSAIDs). Taking too many at once can directly cause kidney damage. Ask your physician if these medications are safe for you especially if you have decreased kidney function.
- Watch your weight: Try to be most days of the week and maintain a healthy weight. If you need to lose weight, talk with your physician about strategies for healthy weight loss. Often this involves increasing daily physical activity and reducing calories.
- Avoid smoking and cigarettes: Cigarette smoke can seriously damage your kidneys and only makes chronic kidney disease worse. If you are finding it hard to quit, talk to your physician about different strategies, or .
As part of your treatment for chronic interstitial nephritis, your physician may recommend a special diet to help support your kidneys. Your physician may refer you to a dietitian who can provide a or suggestions to your current routine that may help your kidneys.
Depending on your situation, kidney function and overall health, your dietitian may recommend the following.
- Avoiding products with added salt: This includes many convenience foods, such as frozen dinners, canned soups, chips, and fast foods. Other foods with added salt include salty snack foods, canned vegetables, and processed meats and cheeses.
- Choosing foods lower in potassium: Your dietitian may recommend that you choose lower potassium foods at each meal. High-potassium foods include bananas, oranges, potatoes, spinach and tomatoes. Examples of low-potassium foods include apples, cabbage, carrots, green beans, grapes and strawberries.
- Limiting the amount of protein you consume: Your dietitian will estimate the appropriate number of grams of protein you need each day and make recommendations based on that amount. High-protein foods include lean meats, eggs, milk, cheese and beans. Low-protein foods include vegetables, fruits, bread and cereals.
When to seek further consultation for interstitial nephritis
Hyperkalemia is a serious complication of chronic interstitial nephritis. If you experience the following symptoms all around the same time, go to the emergency room in order to get the appropriate blood tests and treatments:
- Muscle fatigue
- Abnormal heart rhythms
Questions your doctor may ask to determine interstitial nephritis
- Have you experienced any nausea?
- Are you sick enough to consider going to the emergency room right now?
- Has your fever gotten better or worse?
- Is your fever constant or come-and-go?
- How severe is your fever?
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- Ejaz P, Bhojani K, Joshi VR. NSAIDs and kidney. Journal of the Association of Physicians of India. 2004;52:632-640.
- Types of dialysis. Stanford Health Care.
- Staying fit with kidney disease. National Kidney Foundation.
- How to quit smoking. Centers for Disease Control and Prevention. Updated May 23, 2018.
- Kidney-friendly diet for CKD. American Kidney Fund.