Your kidneys are a pair of organs located toward your lower back. One kidney is on each side of your spine. They filter your blood and remove toxins from your body. Kidneys send toxins to your bladder, which your body later removes toxins during urination.

Kidney failure occurs when your kidneys lose the ability to sufficiently filter waste from your blood. Many factors can interfere with your kidney health and function, such as:

  • toxic exposure to environmental pollutants or certain medications
  • certain acute and chronic diseases
  • severe dehydration
  • kidney trauma

Your body becomes overloaded with toxins if your kidneys can’t do their regular job. This can lead to kidney failure, which can be life-threatening if left untreated.

Usually someone with kidney failure will have a few symptoms of the disease. Sometimes no symptoms are present. Possible symptoms include:

  • a reduced amount of urine
  • swelling of your legs, ankles, and feet from retention of fluids caused by the failure of the kidneys to eliminate water waste
  • unexplained shortness of breath
  • excessive drowsiness or fatigue
  • persistent nausea
  • confusion
  • pain or pressure in your chest
  • seizures
  • coma

Early signs of kidney failure

Symptoms of early stage kidney disease may be difficult to pinpoint. They’re often subtle and hard to identify. If you experience early signs of kidney disease, they may include:

Kidney failure can be the result of several conditions or causes. The cause typically also determines the type of kidney failure.

People who are most at risk usually have one or more of the following causes:

Loss of blood flow to the kidneys

A sudden loss of blood flow to your kidneys can prompt kidney failure. Some conditions that cause loss of blood flow to the kidneys include:

High blood pressure and anti-inflammatory medications can also limit blood flow.

Urine elimination problems

When your body can’t eliminate urine, toxins build up and overload the kidneys. Some cancers can block the urine passageways, such as:

Other conditions can interfere with urination and possibly lead to kidney failure, including:

Other causes

Some other things that may lead to kidney failure include:

  • a blood clot in or around your kidneys
  • infection
  • an overload of toxins from heavy metals
  • drugs and alcohol
  • vasculitis, an inflammation of blood vessels
  • lupus, an autoimmune disease that can cause inflammation of many body organs
  • glomerulonephritis, an inflammation of the small blood vessels of the kidneys
  • hemolytic uremic syndrome, which involves the breakdown of red blood cells following a bacterial infection, usually of the intestines
  • multiple myeloma, a cancer of the plasma cells in your bone marrow
  • scleroderma, an autoimmune condition that affects your skin
  • thrombotic thrombocytopenic purpura, a disorder that causes blood clots in small vessels
  • chemotherapy drugs that treat cancer and some autoimmune diseases
  • dyes used in some imaging tests
  • certain antibiotics
  • uncontrolled diabetes

5 types of kidney failure

There are five different types of kidney failure:

Acute prerenal kidney failure

Insufficient blood flow to the kidneys can cause acute prerenal kidney failure. The kidneys can’t filter toxins from the blood without enough blood flow. This type of kidney failure can usually be cured once your doctor determines the cause of the decreased blood flow.

Acute intrinsic kidney failure

Acute intrinsic kidney failure can result from direct trauma to the kidneys, such as physical impact or an accident. Causes also include toxin overload and ischemia, which is a lack of oxygen to the kidneys.

The following may cause ischemia:

Chronic prerenal kidney failure

When there isn’t enough blood flowing to the kidneys for an extended period of time, the kidneys begin to shrink and lose the ability to function.

Chronic intrinsic kidney failure

This happens when there’s long-term damage to the kidneys due to intrinsic kidney disease. Intrinsic kidney disease develops from a direct trauma to the kidneys, such as severe bleeding or a lack of oxygen.

Chronic post-renal kidney failure

A long-term blockage of the urinary tract prevents urination. This causes pressure and eventual kidney damage.

There are several tests your doctor can use to diagnose kidney failure.

Urinalysis

Your doctor may take a urine sample to test for any abnormalities, including abnormal protein or sugar that spills into the urine.

They may also perform a urinary sediment examination. This test measures the amount of red and white blood cells, looks for high levels of bacteria, and searches for high numbers of tube-shaped particles called cellular casts.

Urine volume measurements

Measuring urine output is one of the simplest tests to help diagnose kidney failure. For example, low urinary output may suggest that kidney disease is due to a urinary blockage, which multiple illnesses or injuries can cause.

Blood samples

Your doctor may order blood tests to measure substances that are filtered by your kidneys, such as blood urea nitrogen (BUN) and creatinine (Cr). A rapid rise in these levels may indicate acute kidney failure.

Imaging

Tests like ultrasounds, MRIs, and CT scans provide images of the kidneys themselves as well as the urinary tract. This allows your doctor to look for blockages or abnormalities in your kidneys.

Kidney tissue sample

Tissue samples are examined for abnormal deposits, scarring, or infectious organisms. Your doctor will use a kidney biopsy to collect the tissue sample. A biopsy is a simple procedure that’s usually performed while you’re awake.

Your doctor will give you a local anesthetic so you don’t feel any pain. They’ll then insert a biopsy needle through your skin and down into your kidney to get the sample. X-ray or ultrasound equipment will locate the kidneys and help your doctor in guiding the needle.

These tests can help determine whether your kidneys are functioning as they should. Other kidney function tests may also help your doctor determine what’s causing the symptoms.

Kidney failure is classified into five stages. These range from very mild (stage 1) to complete kidney failure (stage 5). Symptoms and complications increase as the stages progress.

Stage 1

This stage is very mild. You may experience no symptoms and have no visible complications. Some damage is present.

It’s still possible to manage and slow progression by maintaining a healthy lifestyle. This includes eating a balanced diet, regularly exercising, and not using tobacco products. Maintaining a healthy weight is important, too.

If you have diabetes, it’s important to manage your blood sugar.

Stage 2

Stage 2 kidney disease is still considered a mild form, but detectable issues like protein in urine or physical damage to the kidneys may be more obvious.

The same lifestyle approaches that helped in stage 1 are still used in stage 2. Also talk with your doctor about other risk factors that could make the disease progress more rapidly. These include heart disease, inflammation, and blood disorders.

Stage 3

At this stage kidney disease is considered moderate. Your kidneys aren’t working as well as they should.

Stage 3 kidney disease is sometimes divided into 3A and 3B. A blood test that measures the amount of waste products in your body differentiates between the two.

Symptoms may become more apparent at this stage. Swelling in hands and feet, back pain, and changes to urination frequently are likely.

Lifestyle approaches may help. Your doctor may also consider medications to treat underlying conditions that could speed up failure.

Stage 4

Stage 4 kidney disease is considered moderate to severe. The kidneys aren’t working well, but you’re not in complete kidney failure yet. Symptoms can include complications like anemia, high blood pressure, and bone disease.

A healthy lifestyle is still vital. Your doctor will likely have you on treatments designed to slow damage.

Stage 5

In stage 5, your kidneys are nearing or are in complete failure. Symptoms of the loss of kidney function will be evident. These include vomiting and nausea, trouble breathing, itchy skin, and more.

At this stage you’ll need regular dialysis or a kidney transplant.

There are several treatments for kidney failure. The type of treatment you need will depend on the reason for your kidney failure.

Dialysis

Dialysis filters and purifies the blood using a machine. The machine performs the function of the kidneys. Depending on the type of dialysis, you may be connected to a large machine or a portable catheter bag.

You may need to follow a low-potassium, low-salt diet along with dialysis.

Dialysis doesn’t cure kidney failure, but it can extend your life if you go to regularly scheduled treatments.

Kidney transplant

Another treatment option is a kidney transplant. A transplanted kidney can work normally, and dialysis is no longer needed.

There’s usually a long wait to receive a donor kidney that’s compatible with your body. If you have a living donor the process may go more quickly.

You must take immunosuppressive drugs after the surgery to prevent your body from rejecting the new kidney. These drugs have their own side effects, some of which are serious.

Transplant surgery might not be the right treatment option for everyone. It’s also possible for the surgery to be unsuccessful.

Talk with your doctor about whether you’re a good candidate for a kidney transplant.

There’s no specific diet for people with kidney failure. The guidelines for what you eat will often depend on the stage of kidney disease you have and your individual health. Some recommendations might include:

  • Limit sodium and potassium. Keep track of how much you’re taking in of these two nutrients. Aim to eat fewer than 2,000 milligrams per day of both.
  • Limit phosphorus. Like sodium and potassium, it’s good to keep a cap on the amount of phosphorus you eat in a day. Try to stay below 1,000 milligrams.
  • Follow protein guidelines. In early and moderate kidney disease, you might want to cut back on protein consumption. In end-stage kidney failure, however, you may eat more protein, depending on your doctor’s recommendations.

Beyond these general guidelines, you may also be told to avoid certain foods if you have kidney disease.

The color of your urine is a small window into your body’s health. It doesn’t tell you much about the state of your kidney function until damage to the kidneys has progressed.

Still, changes to urine color may alert you of some issues.

  • Clear or pale yellow. This color indicates you’re well hydrated. This is the ideal color in most cases.
  • Dark yellow or amber. You may be dehydrated. Try drinking more water and cutting down on dark sodas, tea, or coffee.
  • Orange. This could be a sign of dehydration, or it might be a sign of bile in your bloodstream. Kidney disease doesn’t typically cause this.
  • Pink or red. Urine with a pink tint or bit of red could have blood in it. It could also be caused by certain foods, like beets or strawberries. A quick urine test can tell the difference.
  • Foamy. Urine with excess bubbles is a sign that it likely has a lot of protein in it. Protein in urine is a sign of kidney disease.

Urine color can raise flags for potential problems. Learn about the common color causes and what’s most likely to affect the shade of your pee.

Diabetes is the most common cause of kidney failure. Uncontrolled high blood sugar can damage kidneys. The damage can become worse over time.

Diabetic nephropathy, or kidney damage caused by type 1 or type 2 diabetes, can’t be reversed. Managing blood sugar and blood pressure can help reduce damage. Taking medicines prescribed by your doctor is important, too.

If you have diabetes, your doctor will likely perform regular screenings to monitor for kidney failure.

Your risk for diabetic nephropathy increases the longer you live with the condition. Find out what other factors may increase your risk for this type of kidney disease.

It’s not possible to know exactly how long a person with kidney failure will live. Every person with kidney failure is different.

In general, a person on dialysis can expect to live for an average of 5 to 10 years as long as they follow their treatment.

Some factors that play a role in life expectancy are:

  • age
  • stage of kidney disease
  • other coexisting conditions

A young person in midstage kidney failure who has no complicating risk factors or other conditions will likely live longer than an older individual with stage 4 or stage 5 kidney failure plus diabetes or cardiovascular disease.

Once you reach end-stage kidney failure, you will need dialysis to live. Missing even one treatment can decrease your life expectancy.

A kidney transplant is likely to last for about 5 to 10 years. It’s possible to get a second transplant after the first transplant fails.

If you have kidney failure and drink alcohol, your kidneys will be forced to work harder than they already are.

Alcohol doesn’t metabolize out of your system, so you’ll feel its effects until you receive dialysis to filter it out of your blood.

Beer and wine contain large amounts of phosphorous. It can cause severe heart issues and even death if your kidneys are unable to filter it out. However, most hard liquor doesn’t carry the same risk.

If you have kidney failure or late-stage kidney disease, your doctor may recommend you limit how often you drink alcohol. For some people, completely eliminating alcohol from the diet may be best.

Drinking alcohol with kidney failure can hurt the normal function of other organs. Over time, long-term, heavy alcohol use can lead to liver disease.

Alcohol use may cause additional symptoms, such as pain. Find out how drinking alcohol causes back and flank pain.

The prognosis, or outlook, for people with kidney failure depends on several factors. These include the underlying cause, how well that cause is treated, and any complicating factors, like high blood pressure or diabetes.

Proper treatment and healthy lifestyle changes may be able to improve your outlook. Eating a healthy diet, cutting back on kidney-damaging foods, and treating any underlying issues can help extend your health and your life.

There are steps you can take to reduce your risk for kidney failure.

Follow directions when taking over-the-counter medications. Taking doses that are too high (even of common drugs like aspirin) can create high toxin levels in a short amount of time. This can overload your kidneys.

Many kidney or urinary tract conditions lead to kidney failure when they’re not properly managed. You can help reduce your risk for kidney failure by:

  • maintaining a healthy lifestyle
  • following your doctor’s advice
  • taking prescribed medicine as directed
  • treating common causes of kidney failure, such as high blood pressure and diabetes

If you have any concerns about your kidneys, don’t hesitate to reach out to your doctor.