MSD Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Overview of Kidney Filtering Disorders

By

Frank O'Brien

, MD, Washington University in St. Louis

Last full review/revision Jul 2021| Content last modified Jul 2021
Click here for the Professional Version
Topic Resources

Each kidney contains about 1 million filtering units (glomeruli). The glomeruli are made up of many microscopic clusters of tiny blood vessels (capillaries) with small pores. These blood vessels are designed to leak fluid from the bloodstream into a system of miniature tubules. The tubules secrete and reabsorb chemicals and substances from the fluid to cause it to become urine. The urine then drains from the tubules into larger and larger tubes until it leaves the kidney. Normally this filtering system permits fluid and small molecules (but almost no protein or blood cells—Asymptomatic Proteinuria and Hematuria Syndrome Asymptomatic Proteinuria and Hematuria Syndrome Asymptomatic proteinuria and hematuria syndrome is the result of diseases of glomeruli (clusters of microscopic blood vessels in the kidneys that have small pores through which blood is filtered)... read more ) to leak into the tubules. Diseases that affect the kidneys can be divided into three categories based on the way they affect different parts of the kidneys:

Some disorders have features of both glomerulonephritis and nephrotic syndrome.

Viewing the Urinary Tract

Organs of the Urinary Tract

Glomerulonephritis, nephrotic syndrome, and tubulointerstitial nephritis are not specific disorders but rather categories of disorders. Many specific disorders fall within each category, and many specific conditions may cause disorders in each category. For example, membranoproliferative glomerulonephritis is inflammation of kidney filtering cells caused by an immune response. The immune response might be caused by any of several autoimmune disorders, such as systemic lupus erythematosus Systemic Lupus Erythematosus (SLE) Systemic lupus erythematosus is a chronic autoimmune inflammatory connective tissue disorder that can involve joints, kidneys, skin, mucous membranes, and blood vessel walls. Problems in the... read more Systemic Lupus Erythematosus (SLE) (lupus), or by an infection or even cancer.

  • Antibodies (proteins made by the body to attack specific molecules called antigens) may attach directly to cells of the kidneys or molecules trapped in them, causing inflammation.

  • Antibodies attach to antigens outside the kidneys, and these antigen-antibody (or immune) complexes are carried to the kidneys by the bloodstream and get trapped in the glomeruli, causing inflammation.

If enough glomeruli are damaged, kidney function is decreased. As a result, urine production falls and waste products build up in the blood. Also, when damage is severe, inflammatory cells and injured glomerular cells accumulate, compressing the capillaries within the glomeruli and interfering with filtration. Scarring may develop, which also impairs kidney function and reduces urine production. In some cases, tiny blood clots (microthrombi) may form in the small blood vessels, further decreasing kidney function. Rarely, glomerulonephritis can result from a hereditary condition. In other cases, glomerulonephritis is caused by inflammation of the blood vessels (vasculitis Overview of Vasculitis Vasculitic disorders are caused by inflammation of the blood vessels (vasculitis). Vasculitis can be triggered by certain infections or drugs or can occur for unknown reasons. People may have... read more Overview of Vasculitis ).

Nephrotic syndrome Nephrotic Syndrome Nephrotic syndrome is a disorder of the glomeruli (clusters of microscopic blood vessels in the kidneys that have small pores through which blood is filtered) in which excessive amounts of protein... read more causes large amounts of protein to leak from blood into the urine. This leakage can be caused by damage to the glomeruli by inflammatory or noninflammatory processes. In inflammatory processes, red blood cells appear in the urine. Nephrotic syndrome caused by inflammation, therefore, has characteristics similar to those of glomerulonephritis. With noninflammatory processes, no red blood cells appear in the urine. Some forms of nephrotic syndrome can be severe. The glomeruli become scarred, and kidney failure Overview of Kidney Failure Kidney failure is the inability of the kidneys to adequately filter metabolic waste products from the blood. Kidney failure has many possible causes. Some lead to a rapid decline in kidney function... read more (loss of most kidney function) develops. In less severe forms of nephrotic syndrome, kidney function decreases very little.

Tubulointerstitial nephritis Tubulointerstitial Nephritis Tubulointerstitial nephritis is inflammation that affects the tubules of the kidneys and the tissues that surround them (interstitial tissue). This disorder may be caused by diseases, drugs... read more often is caused by a toxic or allergic reaction to a drug. White blood cells or scar tissue appears in the affected kidney. Infection of the kidneys Kidney Infection Pyelonephritis is a bacterial infection of one or both kidneys. Infection can spread up the urinary tract to the kidneys, or uncommonly the kidneys may become infected through bacteria in the... read more (pyelonephritis) can also cause tubulointerstitial nephritis. When inflammation damages the tubules and surrounding tissues, the kidneys may become unable to carry out their normal functions, such as concentrating urine, resulting in urine that is too dilute. The kidneys may also become unable to eliminate (excrete) waste products from the body or balance the excretion of acid, sodium, and other electrolytes, such as potassium. If the damage is severe and affects both kidneys, the result is kidney failure Overview of Kidney Failure Kidney failure is the inability of the kidneys to adequately filter metabolic waste products from the blood. Kidney failure has many possible causes. Some lead to a rapid decline in kidney function... read more .

More Information

The following are some English-language resources that may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Test your knowledge

Urethritis
Urethritis is an infection of the urethra, the tube that transports urine out of the body from the bladder. Many organisms can cause urethritis. Which of the following is an organism that commonly causes urethritis in men, but is more likely to infect reproductive organs in women?  
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
TOP