The kidneys are two bean-shaped, fist-sized organs found just under the ribs on the left and right sides of the spine. They remove impurities and extra water from the blood, filtering 120-150 quarts of blood a day, according to the National Institute of Diabetes and Digestive and Kidney Diseases.
Each kidney consists of thousands of structures called nephrons, where the actual blood filtering takes place. In the nephron, a two-step cleaning process separates what the body needs to keep from what it can get rid of.
A filter called the glomerulus catches blood cells and protein, sending water and waste to a second filter, called a tubule. The tubule captures minerals. After that, what remains leaves the body as urine.
Nephritis describes a condition in which the kidney's tubules and nearby tissues become inflamed, which can lead to kidney damage.
When kidneys are damaged, they don't work properly. Waste builds up and causes serious health problems. If the condition is severe enough, or lasts long enough, it can result in kidney failure.
There are several different types of nephritis.
Acute glomerulonephritis: This form of nephritis can develop suddenly after a serious infection, such as strep throat, hepatitis, or HIV. It can also be caused by lupus and less common conditions such as Goodpasture syndrome or granulomatosis with polyangiitis (GPA). It requires prompt medical attention to prevent kidney damage.
Nephritis can lead to kidney failure if not treated.
Alport Syndrome: This disease can lead to kidney failure, as well as vision and hearing problems. It tends to run in families and is usually more severe in men.
Chronic glomerulonephritis: Developing slowly, and with few symptoms in the early stages, this disease can cause serious kidney damage and kidney failure. It may run in families, or develop after a sudden case of disease.
IgA nephropathy: One of the most common forms of nephritis, aside from those linked to diseases like diabetes and lupus. It develops when deposits of antibodies are formed in the kidney and cause inflammation.
More common in men than women, it is rarely found in young people because early symptoms are easy to miss. It is often treated with blood pressure medications.
Interstitial nephritis: Often developing very rapidly, this form of nephritis is usually caused by medications or infections. It affects the part of the kidney known as the interstitium. If patients are quickly taken off the medication causing the problems, a full recovery is possible in a few weeks.
There are many different causes for nephritis. In some cases, the cause may not be clear. Nephritis and kidney disease can run in families, which suggests a possible genetic link. Infections, such as HIV and hepatitis B or C, can also cause nephritis.
As many as 60 percent of those diagnosed with lupus, an autoimmune disease, also develop nephritis. As a result, there may be a connection with immune system problems.
The most important risk factors for kidney disease are:
- A family history of kidney disease
- High blood pressure
- Heart disease
- Being 60 or older
African-Americans, Hispanics, Native Americans, Alaskan Natives, Asians, and Pacific Islanders are more likely to develop kidney problems than Caucasians.
Symptoms of nephritis are usually not severe in the early stages. However, to protect the kidneys from permanent damage, it's important to seek medical attention if these symptoms are present:
- Changes in urinating habits
- Swelling anywhere in the body, especially the hands, feet, ankles, and face
- Changes in urine color
- Foamy urine
- Blood in the urine
Nephritis may first be detected by routine blood or urine tests. Finding protein in the urine can indicate that the kidneys are not working properly. A blood test that measures a waste product in the blood called creatinine also sheds light on kidney health.
The best way to check for nephritis is to do a biopsy. For this procedure, a doctor uses a needle to remove a piece of the kidney and studies it.
When to see a doctor
Blood in the urine, or urine that looks brown, is a clear signal to seek medical help immediately. Other signs include foamy urine, changes in the frequency of urination, and swelling around the face or ankles. These are symptoms of nephritis.
People should seek medical assistance quickly to limit possible kidney damage if one or more symptoms develop.
Treatment and prevention
The treatment for nephritis depends on whether the disease is acute, chronic, or linked to other diseases, such as lupus.
There are various ways of preventing kidney damage if someone has symptoms of nephritis.
Acute nephritis sometimes goes away on its own. It usually requires treatment with medication and special procedures to remove excess fluids and dangerous proteins.
Treating chronic nephritis typically involves regular check-ups on the kidneys and monitoring blood pressure. Doctors may prescribe water pills to both control blood pressure and reduce any swelling patients have.
Medications that keep the immune system from attacking the kidneys are helpful in some cases. Doctors may also recommend dietary changes, such as cutting back on protein, salt, and potassium.
Acute episodes of nephritis often respond well to treatment. Sometimes, years after an acute episode, individuals develop chronic glomerulonephritis. Although these diseases may not always be curable, proper treatment can keep the disease at bay and protect the kidneys.
It's important to follow a doctor's instructions very carefully to prevent and limit kidney damage.
If kidney failure occurs, the best remaining options are kidney dialysis or a transplant. Dialysis is a medical process that mimics the way healthy kidneys remove waste and excess fluid and maintain safe levels of chemicals in the blood.
Kidney problems make following these healthy guidelines more important than ever:
Monitoring blood pressure is important if kidney problems develop.
- Maintain a healthy weight
- Quit smoking
- Keep blood pressure within healthy limits
- Keep blood sugar within healthy limits
A healthy diet can help protect kidney health. Individuals with kidney problems are frequently advised to eat less protein and cut down on salt.
It can be helpful to talk to a specially trained dietician to learn how to adopt a kidney-friendly diet and avoid medications that harm the kidneys like non-steroidal anti-inflammatories.
What are lupus and lupus nephritis?
Lupus is an auto-immune disease, which means it's a condition in which the body's immune system attacks its own tissues.
More than half of individuals diagnosed with lupus eventually develop lupus nephritis, when the disease causes the kidneys to become inflamed. The symptoms of lupus nephritis include:
- Foamy urine
- High blood pressure
- Swelling of the legs, ankles, and feet
These symptoms may appear along with lupus symptoms, such as joint problems, fevers, and rashes.
Although the severity of lupus can vary between patients and the disease sometimes goes into remission, when lupus affects the kidneys, it's serious. Prompt medical attention is needed to limit further damage to the kidneys.