Interstitial Nephritis: What to Know
Medically reviewed by Kashif J. Piracha, MDMedically reviewed by Kashif J. Piracha, MD
Interstitial nephritis is a condition that causes inflammation in the kidneys' tissues. The kidneys are your body's filtration system, removing waste and excess water from your blood and excreting it as urine. When the kidneys become inflamed due to interstitial nephritis, eliminating waste from the body becomes difficult and leads to additional problems.
This article discusses the symptoms and causes of interstitial nephritis and the diagnostic and treatment process.
Vladimir Vladimirov / Getty Images
Signs and Symptoms of Interstitial Nephritis
Some interstitial nephritis symptoms can make you feel sick or weak, but most people with the condition don't experience pain. This condition creates swelling around the kidneys' filtration system, making filtering waste products from the blood more difficult, though the kidneys still produce urine.
A decrease in urine volume can be the most common symptom of interstitial nephritis. Other symptoms include:
Blood in the urine
Dry mouth and thirst
Feeling nauseated
Feeling tired or confused
Fever
Rash or itchy skin
Swelling in the hands, feet, or legs
Weight gain
What Causes Interstitial Nephritis?
Specific medications, infections, and chronic diseases can cause interstitial nephritis. Healthcare providers classify it into two categories: acute and chronic.
Acute Interstitial Nephritis
Acute interstitial nephritis is the most common type and often is short-lived. Certain medications or drugs often cause acute interstitial nephritis. Some of the most common of which include:
Antibiotics (e.g., penicillin)
Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) (e.g., ibuprofen)
Other medications that decrease stomach acid production (e.g., proton pump inhibitors)
Allergic reactions and infections, like tuberculosis, can also cause acute interstitial nephritis, which can potentially overstimulate the immune system. This overstimulation can cause the immune system to mistakenly attack the areas of the kidneys, resulting in inflammation of the kidneys' tissues.
Chronic Interstitial Nephritis
Chronic interstitial nephritis often lasts months or years. Chronic health conditions, such as autoimmune diseases like lupus or sarcoidosis, or electrolyte level abnormalities in the blood, such as low potassium or high calcium, can cause interstitial nephritis.
Who Is at Risk for Interstitial Nephritis?
The exact mechanism that triggers interstitial nephritis is unknown. However, the following people may be at an increased risk:
People who use over-the-counter (OTC) medications long-term
People with certain autoimmune conditions
People taking specific prescription antibiotics or medications
People with excess calcium or uric acid in their blood
People with not enough potassium in their blood
Knowing if your current medications and medical conditions trigger the condition is essential. Ensure your healthcare provider is aware of all medicines you take so they can monitor you for the development of interstitial nephritis.
How Is Kidney Inflammation Diagnosed?
Healthcare providers begin the diagnostic process for interstitial nephritis with a physical examination, asking about your medical history, and taking blood and urine lab samples for testing. It is important to tell your healthcare provider all components of your medical history and symptoms, including all medications you're taking—even OTC medicines and supplements.
It is difficult for healthcare providers to diagnose interstitial nephritis based on symptoms alone because symptoms tend to be vague and nonspecific (symptoms are general and can be due to many causes). They may test you for other conditions, such as a urinary tract infection (UTI), to rule out other conditions before diagnosing interstitial nephritis.
If your initial workup results indicate a possibility of interstitial nephritis, and they have ruled out other conditions, your healthcare provider will likely order a kidney biopsy to confirm the diagnosis. A small piece of kidney tissue is removed and examined under a microscope during the biopsy.
How Is Interstitial Nephritis Treated?
The most common cause of acute interstitial nephritis is medication, so stopping the drug allows the nephritis to resolve on its own. If it does not resolve, your healthcare provider might order a course of corticosteroids to help reduce inflammation. Despite these interventions, some people with acute interstitial nephritis might require short-term dialysis to help relieve the kidneys' workload and allow them to recover.
It is essential to treat the underlying condition if you have chronic interstitial nephritis caused by chronic conditions. If interstitial nephritis significantly impacts your kidneys, you may experience elevated blood pressure and need medications to control it and reduce your kidneys' workload.
People with significant kidney damage and tissue scarring due to chronic interstitial nephritis may require short- or long-term dialysis to ensure waste products are adequately cleared from the body.
Lifestyle Changes and Self-Care Measures
Lifestyle changes and self-care measures related to interstitial nephritis are more about protecting the kidneys from stress and being overworked than directly impacting the condition. Some lifestyle changes include:
Eating a kidney-friendly diet by including fruits and vegetables, lean proteins, incorporating whole grains, avoiding added salt and excess sugar, and drinking plenty of fluids
Staying active, including by walking, for at least 30 minutes daily for five or more days each week
Keeping your blood pressure healthy, generally less than 120/80 millimeters of mercury. (mmHg), to prevent damage to the blood vessels in the kidneys
Improving your mental health
Limiting alcohol intake to prevent the kidneys from working too hard
Eliminating tobacco products, which can damage the blood vessels throughout the body, including the kidneys
What Is the Outlook for Someone With Interstitial Nephritis?
When caught early, most people with interstitial nephritis will regain kidney function. However, when left untreated for too long, it can cause scarring in the kidneys for up to 40% to 50% of people.
The primary prevention strategy is to know the risks associated with certain medications and medical conditions that tend to be associated with interstitial nephritis. Educating yourself on medication usage and side effects is vital to ensure you are taking them as directed.
Notify a healthcare provider immediately if you take medications or have a medical condition associated with interstitial nephritis and begin experiencing symptoms. They can help you detect interstitial nephritis early and potentially avoid kidney damage.
If interstitial nephritis significantly impacts your kidneys, you may experience elevated blood pressure and require medications to keep it controlled. People who need dialysis may have to adjust their lifestyle, as it's vital to receive treatments as scheduled to maintain optimal health and wellness.
Potential Complications
The biggest complication of interstitial nephritis is impaired kidney function due to scarring. If you have extensive scarring, you may experience complications such as:
Anemia (low red blood count or function)
Elevated blood pressure requiring lifestyle changes and medication management
Glomerulopathy (a rare, inflammatory kidney disease)
Nephrotic syndrome (an abnormality that indicates kidney dysfunction)
Tubular atrophy (a chronic kidney injury)
Summary
Certain medications, as well as chronic health conditions, can contribute to interstitial nephritis, although the exact mechanism is unknown. Prevention includes understanding the side effects and dosing of your medications and managing any chronic conditions you have with your healthcare team. Early intervention can help prevent long-term kidney damage. Notify a provider of any concerning symptoms.
Read the original article on Verywell Health.
