Most people know that a major function of the kidneys is to remove waste products and excess fluid from the body. There are two kidneys, each about the size of a fist, located on either side of the spine at the lowest level of the rib cage. Each kidney contains up to a million functioning units called nephrons. A nephron consists of a filtering unit of tiny blood vessels called a glomerulus attached to a tubule. When blood enters the glomerulus, it is filtered and the remaining fluid then passes along the tubule. In the tubule, chemicals and water are either added to or removed from this filtered fluid according to the body’s needs, the final product being the urine we excrete.
The kidneys perform their life-sustaining job of filtering and returning to the bloodstream about 200 quarts of fluid every 24 hours. About two quarts are removed from the body in the form of urine, and about 198 quarts are recovered. The urine we excrete has been stored in the bladder for anywhere from 1 to 8 hours.
Chronic kidney disease (CKD) is a major public health concern. CKD often goes undetected until it is very advanced (when someone would need dialysis or a transplant). But when it is diagnosed early through very simple tests, progression of CKD can be slowed or even stopped. Know your kidney score! Regular testing for everyone is important but it is especially important for people at risk. Follow these 6 steps to learn more about kidney disease, your risk, and how to prevent kidney disease.
Step 1: Know These Facts
6 things healthy kidneys do:
• Regulate the body’s fluid levels
• Filter wastes and toxins from the blood
• Release a hormone that regulates blood pressure
• Activate Vitamin D to maintain healthy bones
• Release the hormone that directs production of red blood cells
• Keep blood minerals in balance (sodium, phosphorus, potassium)
8 Problems CKD Can Cause:
• Cardiovascular disease
• Heart attack and stroke
• High blood pressure
• Weak bones
• Nerve damage (neuropathy)
• Kidney failure (end-stage renal disease,
• Anemia or low red blood cell count
Step 2: Assess Your Risk
4 Main Risk Factors:
• Diabetes (self or family)
• High blood pressure (self or family)
• Cardiovascular disease (self or family)
• Family history of kidney disease or diabetes or
high blood pressure
10 Additional Risk Factors:
• African-American heritage
• Native American heritage
• Hispanic, Asian, Pacific Islander heritage
• Age 60 or older
• Low birth weight
• Prolonged use of NSAIDs, a type of painkillers, such as ibuprofen and naproxen
• Lupus, other autoimmune disorders
• Chronic urinary tract infections
• Kidney stones
Step 3: Recognize Symptoms
8 Possible Trouble Signs:
Most people with early CKD have no symptoms, which is why early testing is critical. By the time symptoms appear, CKD may be advanced, and symptoms can be misleading. Pay attention to these:
• Fatigue, weakness
• Difficult, painful urination
• Foamy urine
• Pink, dark urine (blood in urine)
• Increased thirst
• Increased need to urinate (especially at night)
• Puffy eyes
• Swollen face, hands, abdomen, ankles, feet
Step 4: Get Tested
If you or a loved one belong to a high-risk group, ask your primary-care physician about these tests—and be especially insistent about the last one. Your doctor may want to perform other tests as well.
4 Simple, Life-Saving Tests:
• Blood Pressure: High blood pressure can damage small blood vessels (glomeruli) in the kidneys. It is the second-leading cause of kidney failure after diabetes.
• Protein in Urine: Traces of a type of protein, albumin in urine (albuminuria) is an early sign of CKD. Persistent amounts of albumin and other proteins in the urine (proteinuria) indicate kidney damage.
• Creatinine in Blood (Serum Creatinine): Healthy kidneys filter creatinine (a waste product from muscle activity) out of the blood. When kidney function is reduced, creatinine levels rise.
• Glomerular Filtration Rate (GFR): This is the most sensitive and accurate gauge of kidney function. Doctors measure blood creatinine levels and perform a calculation based on age, race, and gender.
Step 5: Stay Healthy
6 Things People with CKD Should Do:
• Lower high blood pressure
• Keep blood-sugar levels under control if diabetic
• Reduce salt intake
• Avoid NSAIDs, a type of painkillers
• Moderate protein consumption
• Get an annual flu shot
9 Things Everyone Should Do:
• Exercise regularly
• Control weight
• Follow a balanced diet
• Quit smoking
• Drink only in moderation
• Stay hydrated
• Monitor cholesterol levels
• Get an annual physical
• Know your family medical history
Step 6: Learn More
To learn more about CKD risk factors, prevention and treatment, visit www.kidney.org.
Which drugs are harmful to your kidneys?
Every drug you put into your body passes through your kidneys. If the drug is not taken following your healthcare provider’s instructions, or if it is an illegal substance, it can cause injury to the kidneys.
Your kidneys could be damaged if you take large amounts of over-the-counter medications, such as aspirin, acetaminophen and ibuprofen. None of these medicines should be taken daily or regularly without first talking to your healthcare provider. Thousands of Americans have damaged their kidneys by using these medicines regularly for too long.
Heavy drinking can hurt both your kidneys and your liver. Alcoholics have a high risk of developing both kidney and liver failure.
Antibiotics can also be dangerous if they are not taken correctly. People with kidney disease need to take a smaller amount of antibiotics than people with healthy kidneys. Take only medicines ordered for you by your healthcare provider.
In general, over-the-counter laxatives are safe for most people. However, some prescription laxatives that are used for cleaning the bowel (usually before a colonoscopy) can be harmful to the kidneys.
Contrast Dye (used in some diagnostic tests such as MRIs)
Some medical tests called “imaging tests” contain a type of dye called “contrast dye.” Examples of imaging tests are MRIs and CT-scans. Contrast dyes can be harmful to people who have kidney disease. Not all imaging tests contain contrast dyes.
Most street drugs, including heroin, cocaine and ecstasy can cause high blood pressure, stroke, heart failure and even death, in some cases from only one use. Cocaine, heroin and amphetamines also can cause kidney damage.
What should you do?
• Do not take any medicine, drug or substance unless you are under a healthcare provider’s supervision.
• If you need to have an imaging test or colonoscopy, let your healthcare provider know if you have kidney disease or are at risk for getting it.
Alcohol and Your Kidneys
Drinking alcohol can affect many parts of your body, including your kidneys. A little alcohol—one or two drinks now and then—usually has no serious effects. But drinking too much can harm your health. It can also worsen kidney disease.
How does alcohol harm the kidneys?
Your kidneys filter harmful substances from your blood. One of these substances is alcohol. Alcohol can cause changes in the function of the kidneys and make them less able to filter your blood. In addition to filtering blood, your kidneys do many other important jobs. One of these jobs is keeping the right amount of water in your body. Alcohol affects the ability of your kidneys to do this. When alcohol dehydrates (dries out) the body, the drying effect can affect the normal function of cells and organs, including the kidneys.
Too much alcohol can also affect your blood pressure. People who drink too much are more likely to have high blood pressure. And medications for high blood pressure can be affected by alcohol. High blood pressure is a common cause of kidney disease. More than two drinks a day can increase your chance of having high blood pressure.
How much alcohol is too much?
When experts talk about one drink, they are talking about one 12-ounce bottle of beer, one glass of wine (5 ounces), or one shot (1.5 ounces) of “hard liquor.” Having more than three drinks in a day (or more than seven per week) for women, and more than four drinks in a day (or more than 14 per week) for men, is considered “heavy” drinking. The kidneys of heavy drinkers have to work harder. Heavy drinking on a regular basis has been found to double the risk for kidney disease.
Some people should not drink at all. Ask your healthcare provider if it is safe for you to drink, especially if you have a medical condition or take medicines that might be affected by using alcohol.
A good guideline is: no more than one to two drinks a day for men and one drink a day for women and people over 65.