About the Kidneys

The kidneys are bean-shaped organs about the size of your fist.

There are normally two and they lie deep in the lower abdomen on either side of the spine. They perform many critical functions, including:

  • Filtering the blood and in helping maintain normal levels of important minerals and electrolytes
  • Helping control water content in the body
  • Contributing hormones into the circulation that can affect blood pressure

The kidneys have collecting systems for gathering urine and are connected to long muscular tubes, called ureters, that transmit urine into the bladder for storage and later excretion.

About Kidney Disease

Many different kinds of diseases aside from kidney cancer can affect the kidneys, ureters, bladder, and the vessels that supply blood to and drain blood from these organs. These include:

  • Acute and chronic infections
  • Autoimmune diseases
  • Clotting disorders that can affect the renal arteries or veins
  • Trauma
  • Kidney (renal) stone disease
  • A host of developmental and congenital disorders

Medical imaging continues to play a critical role in both the initial diagnosis and treatment follow-up for most kidney diseases. Imaging exams greatly aid in pre-surgical planning, especially in patients being considered for renal donation (transplant), urethral obstruction, and stone disease. Imaging exams are also helpful in evaluating patients who have already received a transplanted kidney.

Facts About Kidney Disease

Following are some facts about a few of the many conditions that can affect the kidneys.

  • According to the National Kidney Foundation, more than 26 million Americans have kidney disease. That’s one in nine adults.
  • Symptoms of chronic kidney disease don’t usually arise until kidney function is less than 25% of normal.
  • Chronic kidney disease is on the rise. One reason is that it is linked to diabetes and hypertension, which are both increasingly common.
  • Polycystic kidney disease affects almost 1 in 1000 Americans.
  • Serious complications of polycystic kidney disease include hypertension and kidney failure. It is the fourth leading cause of kidney failure.
  • 1 in 10 Americans will have at least one kidney stone sometime during their life.
  • White Americans are more likely to develop kidney stones than African Americans.
  • Men are much more likely to develop kidney stones than women.

Risk Factors and Symptoms

Risk Factors for Kidney Disease

Following are the risk factors for some kidney conditions:

Chronic Kidney Disease

Diabetes is the single greatest risk factor for chronic kidney disease. Following are some additional risk factors for chronic kidney disease:

  • High blood pressure
  • Family history of any type of kidney problems
  • Sickle cell disease
  • Lupus
  • Atherosclerosis
  • Chronic glomerulonephritis
  • Congenital nephrotic syndrome
  • Polycystic kidney disease
  • Drug overdose
  • Excessive alcohol consumption
  • Long-term use of pain medications, such as aspirin, acetaminophen, and ibuprofen
  • Treatment with the antibiotics streptomycin or gentamicin
Polycystic Kidney Disease

Polycystic kidney disease is caused solely by abnormal genes.

Kidney Stones

Following are some risk factors for developing kidney stones:

  • Insufficient fluid intake, especially water
  • Personal history of kidney stones
  • Family history of kidney stones
  • Between the ages of 20 and 60
  • High protein, low fiber diet
  • Very sedentary lifestyle
  • Recurring urinary tract infections

Reducing the Risk

Following are ways you can reduce your risk for some kidney conditions:

Chronic Kidney Disease

It may not be possible to prevent chronic kidney disease; however, you may reduce your risk in the following ways:

  • Limit alcohol consumption
  • Don’t abuse drugs
  • If you have a condition that increases your chances of chronic kidney failure, follow your doctor’s recommendations carefully
Polycystic Kidney Disease

There are no ways to reduce the risk of PKD since it is solely an inherited illness. However, the disease varies in severity and it is possible to lessen or prevent some of the complications.

Kidney Stones

You may prevent kidney stones by making some lifestyle changes, including those listed below. If lifestyle changes don’t suffice, your doctor may prescribe medication.

  • Drink at least 3½ quarts of fluid, preferable water, every day; more if you live in a hot, dry climate
  • Restrict foods high in oxalates, including meat (especially organ meat), chicken, certain fish, chocolate, and berries
  • Restrict your salt intake

Symptoms of Kidney Disease

Following are symptoms for some kidney conditions:

Chronic Kidney Failure

Over time, chronic kidney failure can lead to other serious conditions. Unfortunately, symptoms often don’t occur until irreversible damage has been done. Following are some symptoms of chronic kidney failure:

  • High blood pressure
  • Unexplained weight loss
  • Anemia
  • Nausea or vomiting
  • Fatigue
  • Unexplained headaches
  • Decreased urine output
  • Decreased mental sharpness
  • Muscle twitches and cramps
  • Bleeding in the intestines
  • Yellowish-brown cast to the skin
  • Persistent itching
  • Difficulty sleeping
Polycystic Kidney Disease

Following are some of the symptoms of PKD:

  • High blood pressure
  • Back or side pain related to enlarged kidneys
  • Abdominal pain swelling
  • Blood in your urine
  • Kidney stones
  • Kidney failure
  • Kidney or frequent urinary tract infections
  • Brain aneurysm
  • Diverticulosis
  • Liver or pancreatic cysts
  • Abnormal heart valves
Kidney Stones

Kidney stones often don’t have symptoms until they become large, cause a blockage, are being passed, or are associated with an infection. In these cases, the most common symptom is intense pain that may fluctuate. The pain usually starts in the back and may radiate down to the groin as the stone travels through the ureter to the bladder. Additional symptoms include:

  • Bloody, cloudy or foul-smelling urine
  • Nausea and vomiting
  • Persistent urge to urinate
  • Burning during urination
  • Fever and chills

Diagnosis and Treatment

Diagnosing Kidney Disease

CT, ultrasound, MRI, conventional catheter angiography and nuclear medicine all have different roles to play and are often complimentary in the work-up of kidney disease.

CT scans are used most often to evaluate the kidneys, especially in the evaluation of trauma patients and patients with suspected kidney stones. CT and MRI are both very good in the evaluation of the renal arteries. CT urograms (an x-ray exam using contrast material) are also used to evaluate patients with certain types of cancer. This study provides diagnostic information about the kidneys, ureters and bladder with one test and has largely replaced a combination approach with multiple exams used in the past for certain types of patients.

Ultrasound is also often used to evaluate kidney abnormalities with the added benefit of no ionizing radiation. Ultrasound is a fast, noninvasive way to evaluate the size and contour of the kidneys as well as to assess the renal vessels and detect obstruction of the kidneys from a variety of causes. Nuclear medicine renal scans play an important part in the workup of unexplained hypertension, obstruction, renal transplant complications and the staging and follow-up of cancer patients. Glomerular Filtration Rate is a nuclear medicine exam that is used to determine how well the kidneys are functioning.

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