Nephritis: Causes, Symptoms & Treatment

Nephritis is a type of kidney inflammation that affects the glomeruli, which are responsible for filtering waste and excess fluids from the blood. When these structures are damaged, toxins can build up in the body and affect overall health.

Nephritis can be caused by infections, medications, toxins, or autoimmune diseases such as lupus, and may also occur as a complication of conditions like hepatitis or HIV. Common symptoms include decreased urine output, swelling in the legs or face, high blood pressure, and blood in the urine.

Diagnosis is made by a nephrologist using tests such as urine analysis, imaging exams, or a kidney biopsy. Treatment depends on the specific type and cause and may include medications, dietary changes, and blood pressure control to help prevent complications like chronic kidney disease.

Main symptoms

The most common symptoms of nephritis include:

• Decreased urine output

• Blood in the urine

• Excessive sweating, especially of the face, hands, and feet

• Swelling of the face or legs

• Increased blood pressure

Chronic nephritis can cause symptoms such as loss of appetite, nausea, vomiting, fatigue, difficulty sleeping, itching, and muscle cramps.

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), these same symptoms are also seen in more advanced kidney disease.

Confirming a diagnosis

To confirm the diagnosis, it is important to see a nephrologist (kidney specialist). The doctor may order tests such as a urine test, ultrasound, CT scan, and, if needed, a kidney biopsy to identify the problem and begin appropriate treatment.

Different types

Nephritis can be classified based on which part of the kidney is affected or what is causing the problem:

• Glomerulonephritis: Inflammation mainly affects the first part of the kidney’s filtration system, the glomerulus, and can be acute or chronic.

• Interstitial nephritis: Inflammation occurs in the renal tubules and in the space between the tubules and the glomeruli.

• Lupus nephritis: The glomeruli become inflamed as a result of lupus, an autoimmune disease.

The doctor can determine the type of nephritis, which helps guide the most appropriate treatment.

Possible causes

There are many possible causes of nephritis, such as:

• Excessive use of certain medications, including analgesics, antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), diuretics, anticonvulsants, and calcineurin inhibitors like cyclosporine and tacrolimus

• Infections caused by bacteria, viruses, or other microorganisms

• Autoimmune diseases, such as lupus, Sjögren syndrome, and IgG4-related disease

• Prolonged exposure to toxins such as lithium, lead, cadmium, or aristolochic acid

In addition, people who have other kidney conditions related to cancer, diabetes, HIV, or sickle cell anemia are at higher risk of developing nephritis.

Treatment options

Treatment depends on the specific type of nephritis. Acute nephritis is usually managed with complete rest, blood pressure control, and reduced salt intake, and if it is caused by an infection, antibiotics may also be needed.

In chronic nephritis, treatment typically includes blood pressure control, anti-inflammatory medicines (such as corticosteroids), immunosuppressants, and diuretics, along with a diet low in salt, protein, and potassium.

According to the NIDDK, chronic kidney disease develops when the kidneys are damaged and can no longer filter blood the way they should, which is why the nephrologist may recommend regular follow-up visits.

Prevention measures

To help prevent nephritis, you should avoid smoking, manage stress, and not take any medications that have not been prescribed by a healthcare provider, as these factors can contribute to kidney damage.

People with other health conditions, especially autoimmune diseases, should follow their prescribed treatment and see their provider regularly for blood pressure checks and blood tests.

Your provider may also recommend dietary changes, such as reducing your overall intake of protein, salt, and potassium.