Kidney failure is the more or less significant decrease in the functions of the kidneys. The kidney is a vital organ that serves mainly to rid the body of harmful waste. Kidney failure is, therefore, life-threatening. 

The kidneys filter the blood, they regulate minerals, they maintain the water balance of the body and the acid-base balance in the blood, and finally, they produce hormonesvitamins, and enzymes essential for the production of red blood cells, the regulation of blood pressure and the fixing of calcium.   

There are two types of kidney failure:

  • Acute kidney failure
  • Chronic kidney failure

Chronic kidney failure results from the progressive and irreversible destruction of the kidneys. The causes are diverse and combine genetic, environmental, and degenerative factors. 

Acute kidney failure refers to an abrupt onset and potentially reversible damage of one or both kidneys.

Causes of kidney failure


Diabetes damages the kidneys. Indeed, excess sugars in the blood gradually damage the small blood vessels of the kidneys which can no longer properly perform their filter function. This also leads to renal permeability, where proteins are able to reach the urine. Ultimately, if the nephropathy is not taken care of and the diabetes is not stabilized, the kidney filters can be so damaged by excess sugar that the kidneys stop working altogether.

In addition, diabetes can also damage the nerves controlling the urinary system, causing difficulty in passing urine and pressure in the bladder, which can then cause damage to the kidneys. 

Finally, bacteria love sugar. Diabetics, therefore, have a favorable environment for the proliferation of bacteria and therefore for kidney infections.

High blood pressure

When hypertension (high blood pressure) is chronic and therefore poorly treated, unbalanced, in some of the patients affected it causes progressive sclerosis of the kidney vessels, resulting in severe chronic kidney failure, requiring frequent dialysis or kidney transplantation.


Kidney failure can also result from an inherited genetic disease affecting the kidneys. Polycystic kidney disease is the most common of them accounting for about 2 in 100 cases of kidney failure in the United States. It is characterized by the gradual appearance of cysts along the tubule which collects the waste filtered by the glomerulus. As they proliferate and grow in size, these cysts invade the kidneys and prevent their normal functioning. 

Infection of the kidneys (pyelonephritis)

Pyelonephritis (kidney infection) can also be the cause of kidney failure. The disease results from repeated bacterial infections of the upper urinary tract, often with E. coli, affecting one or both kidneys. 

Polycystic kidney disease

Polycystic kidney disease is an inherited genetic disease affecting the kidneys. It is characterized by the formation of cysts in the kidneys. This phenomenon leads to an enlargement (increase in volume) of both kidneys which can lead to kidney failure.

Obstruction of the urinary tract

Urinary tract obstruction is a blockage that inhibits the flow of urine on its normal path (the urinary tract), including the kidneys, ureters, bladder, and urethra. The blocking can be total or partial. It can cause kidney damage, kidney stone formation, and infection and lead to kidney failure.

Reflux nephropathy

Reflux nephropathy is scarring of the kidneys caused by urine passing backward from the bladder through the ureter and to a kidney. Reflux nephropathy is asymptomatic, but people with reflux nephropathy tend to develop UTIs, chronic kidney disease, kidney failure.


Many drugs are able to affect the kidneys negatively. Preventing, identifying, and managing the nephrotoxicity of these drugs is essential to limit drug-induced kidney damage and its consequences.

Drugs that can affect the way the kidneys work are called nephrotoxic drugs. They are divided into two categories, depending on the kidney damage they cause:

  • Drugs responsible for functional renal failure: These drugs include diuretics, non-steroidal anti-inflammatory drugs or certain antihypertensives. The problem caused by these drugs usually goes away when the offending medication is stopped.
  • Medicines responsible for organic renal failure: The drugs can cause irreversible kidney tissue damage. These drugs are, for example, certain antibiotics (aminoglycosides), cytotoxic drugs, immunosuppressants, lithium or iodinated contrast agents.

Kidney Failure Symptoms

1. Frequent need to urinate

One of the main kidney failure symptoms is the frequent need to urinate. This is medically referred to as pollakiuria.  However, be careful, there is often confusion between polyuria and pollakiuria. Pollakiuria is characterized by the need to urinate more often with the passage of small quantities of urine whereas polyuria refers to a persistently excessive flow of watery urine, with low specific gravity and without the presence of either protein or sugar.

2. Cloudy urine

When the kidneys no longer perform their filtering function effectively, proteins can reach the urine. This will give the urine a cloudy look.

3. Shortness of breath

Kidney failure can also cause shortness of breath. Shortness of breath is linked to the kidneys in two ways. Extra fluid in the body might first accumulate in the lungs. Second, anemia (a lack of oxygen-carrying red blood cells) can leave your body depleted of oxygen and make you feel out of breath.

4. Bad breath

If your breath smells bad like ammonia and everything tastes like metal, you may have kidney disease.

These symptoms can take place due to the accumulation of toxins in the blood due to kidney failure.

5. Lower back pain

Pain in the lower back is also one of the main symptoms of kidney problems. This may indicate the presence of kidney stones, kidney failure, or an infection.

6. Loss of appetite

Compounds build up in the blood in the early to middle stages of renal disease can suppress hunger and affect your perception of taste. Foods that you used to love may begin to taste metallic. Appetite loss can be caused by depression, anxiety, medicines, and other therapies.

7. Nausea & vomiting

Nausea can occur when the kidneys work very poorly: at less than 20% of capacity. A lot of waste products remain in your blood.

Because of the waste products, you will experience nausea, vomiting, a loss of appetite, etc. Nausea can also occur when the blood gets too acidic. Due to kidney damage, the kidneys are no longer able to maintain the acidity balance.

8. Persistent itching

A kidney problem can lead to an itchy rash because the kidneys do not remove waste products from our blood as they should. These waste products then accumulate in the blood and cause itching.

Of course, rashes can have all kinds of other causes: eczema, psoriasis, liver problems, herpes, allergies… Consult a doctor or a dermatologist to be sure.

9. Muscle cramps

Muscle cramps in the arms and legs are common in kidney damage. Especially at night. This is due to multiple factors, including:

  • Accumulation of waste products: Due to the kidney damage, more waste products remain in the body. Also, in the muscles. To accelerate drainage, the muscles quickly contract, causing the cramps.
  • Damage to the nerves: The accumulated waste products also affect the nerves. A consequence of this can be that the nerves control the muscles incorrectly. For example, they instruct the muscles to contract quickly. This causes cramping.
  • Salt deficiency: The kidneys regulate the amount of salts in the body. Think potassium, magnesium and bicarbonate. In the initial stages of chronic kidney damage, more salts are lost through the urine. A shortage of these salts can cause cramps.

Certain medications also increase the risk of cramping. For example, water pills (against high blood pressure) and statins (against high cholesterol).

10. Swelling Of the Eyelids and Ankles

Edema of the eyelids, ankles, and/or feet may be a sign of kidney dysfunction. When the kidneys are functioning well, they participate in a balance that constantly maintains the amounts of serum (plasma water) in the blood and tissues.

When the kidneys no longer perform this function, the kidneys pass protein from the blood into the urine. This creates an imbalance and the serum that was in the blood tends to pass into the surrounding tissues, causing edema.

When the kidneys stop making urine, the water is no longer eliminated, so undeniably you swell all over the place. This can involve weight gain and increased blood pressure.

11. Tiredness

People with kidney failure will experience fatigue and low energy. There are several things that contribute to this fatigue such as anemia, iron deficiency, and accumulation of waste products in the blood.

Fatigue can start at an early stage, even if kidney function is still reasonably good. As the kidney damage worsens, fatigue also increases.

Often the fatigue is already there when you wake up. That’s because the quality of sleep also decreases with kidney problems.

12. Weak bones

Calcium, phosphate, vitamin D, and the parathyroid hormone PTH are needed for strong bones. The kidneys provide the right amount of these substances in the body. In the case of kidney damage, this is no longer possible. As a result, the bones weaken. This is called renal osteodystrophy.

At first, you won’t notice that your bones are getting weaker. But in the long run, you’re more likely to have bone fractures and the fractures will take longer to heal. You can also experience pain in the bones. In children, growth disorders and abnormalities of the skeleton occur.

13. High blood pressure

High blood pressure and kidney damage reinforce each other. The kidneys indeed help to regulate blood pressure. Damaged kidneys can no longer do that properly. Among other things, they make too much of the hormone renin and stimulate the nervous system that co-regulates blood pressure. As a result, blood pressure rises. Furthermore, due to kidney damage, too much water and salt remain in the body. This also increases blood pressure. The kidneys are then further damaged.

Inversely, when blood pressure is too high for a long time, blood vessels all over the body are affected. This damage leads to narrowing or clogging of the blood vessels and a decrease of blood to the organs decreases. This can lead to damage to the kidneys, but also to the heart, brain, and other blood vessels.

14. Loss of sexual desire

If your kidneys are not working properly, it can also lead to sexual problems. Kidney damage may make you less able to enjoy sex and intimacy.

Sexual problems are common in kidney patients. Both in men and in women. Among other things, you may experience the following issues.

  • You don’t feel like having sex.
  • You are less likely to get excited.
  • Men sometimes get erection problems. It is then more difficult to get and keep the penis stiff.
  • In women, the vagina sometimes does not become moist with sexual arousal. Sexual intercourse can then be painful.
  • The experience of orgasm also changes.

This is explained by multiple factors:

  • The kidney damage and the treatments can make you feel very tired. As a result, you probably have less desire to make love.
  • The accumulated waste products damage the nerves. The genitals are therefore less sensitive to sexual stimuli.
  • The kidney damage can disrupt the hormone balance. The amount of testosterone goes down, in men and in women. This reduces the desire for sex.
  • Kidney damage is often accompanied by high blood pressure. High blood pressure can lead to erection problems in men. It is also more difficult for women to become sexually aroused.
  • Medications can play a role in sexual problems. A low sex drive may be a side effect of your medications.

15. Sleep apnea

Sleep apnea is relatively common in people with kidney damage. Especially in people who dialyze.

Sleep apnea refers to a sleep disorder where the sleeper suffers from breathing pauses or decreased respiratory flow. This happens several times a night. You usually do not notice the breathing pauses yourself. The body recovers immediately. But you do sleep less deeply. As a result, you are tired and sleepy during the day.

It’s not entirely clear why so many kidney patients have sleep apnea. All kinds of things play a role. Such as the dysregulation of the hormone system in the kidneys. There is also a relationship between overweight and diabetes mellitus, conditions that kidney patients sometimes also have to deal with.

The oxygen deficiency in apnea contributes to high blood pressure, which also accelerates the deterioration of the kidneys.

16. You get infected more easily

With chronic kidney damage, the immune system works less well. You are therefore more susceptible to infections including the flu, bladder infection, blood poisoning, and pneumonia.

The following things may play a role:

  • Protein loss through urine: Some kidney patients lose protein through the urine. In this way, proteins that play a role in the immune system also disappear. As a result, your immunity weakens.
  • Change in white blood cells: The white blood cells are part of the immune system. In dialysis patients, the white blood cells are altered. Due to the changes, the blood cells work less well, weakening the immune system.

17. Acidification of your blood

Damaged kidneys are not able to filter acidic substances from the blood well. This causes the blood to acidify. The blood has a certain acidity (also called pH). This is determined by substances in the blood. These are acidic and basic substances. The basic substances neutralize the acidic substances. The body strives to keep the pH value of the blood between 7.35 and 7.45.

Due to this acidification of the blood, you can get all kinds of complaints. For example:

  • Fatigue
  • Lack of energy
  • Nausea
  • Accelerated osteoporosis
  • Muscle weakness
  • Shortness of breath

The kidneys play an indispensable role in maintaining the acidity balance. They ensure that the acidity remains stable. But damaged kidneys can no longer do that well.

How to protect your kidneys

Eat healthy

Good kidney health starts with your diet. Eating a balanced diet helps prevent overweight, diabetes, and high blood pressure, all of which promote kidney disease.

An Australian study from September 2019, published in the Journal of American Society of Nephrology, confirms that the Mediterranean diet is best indicated. Opting for a diet rich in fruits and vegetables, nuts or almonds, whole grains, legumes, and fish would indeed reduce the risk of kidney disease by 30% according to the researchers.

Also add some berries and fermented dairy products to your menu to protect your urinary microbiota, the imbalance of which is the cause of many kidney diseases including stones, cystitis, and urinary incontinence.

Drink plenty of water

Also, remember to hydrate yourself well. The body needs 1.5 liters of water per day. In general, there is no need to go beyond this recommendation except in cases of extreme heat, sweating, or diarrhea. Another exception: people who tend to suffer from urinary tract infections or kidney stones should dilute their urine further and drink around 2 liters per day for this. In this volume, we include not only water but also tea, coffee, herbal teas, and all liquids as long as they are without added salt or sugar.

Limit you salt intake

In the west, and especially in the United States, we consume an excessively high amount of salt on average, around 3.4 g per day. However, excess salt consumption is one of the main causes of hypertension, which itself is one of the major causes of progressive kidney damage. A salt intake of 1.5g per is recommended by the American Heart Association. To enhance the taste of your dishes, you can easily replace salt with gomashio, spices, or herbs.

Avoid toxic substances

Be careful with self-medication. Overuse of non-steroidal anti-inflammatory drugs, such as ibuprofen, also poses a threat to the kidneys, as they reduce the size of the blood vessels that supply them.

This is why it is recommended to use them at the minimum effective dose for the shortest duration: no more than 3 days in case of fever and no more than 5 days in case of pain. The same goes for laxatives and diuretics.

You should also avoid so-called “healing” herbs, food supplements, and more generally any product whose composition is not clearly identified.

If you are a smoker, stop smoking. The latter causes the deterioration of kidney function and increases the risk of developing kidney failure fourfold.

Engage in physical activity

To preserve your kidneys, it is essential to practice physical activity. The recommendation from experts is 10,000 steps or 30 minutes of activity per day minimum.

It is also recommended to not go more than 48 hours without having practiced a physical activity. This helps, whatever the age, to reduce the risk of cardiovascular disease, diabetes, but also obesity.

There is no age to start regular physical activity. You have to go gradually, starting with a moderate activity that you like (gardening, DIY, etc.). Walking, for example, is easy to do every day. Find out more from clubs and meetup groups near you that offer such activities (hiking, dancing, water aerobics) in a friendly atmosphere.

Also, never go beyond your limits. Allow 5–10-minute warm-up and cool-down times.

Finally, some good habits also allow you to increase your daily physical activity. You can, for example, avoid taking the elevator, start walking the dog more often, or park your car a bit further than you usually do.

Get tested

Kidney disease is said to be “silent” because it does not manifest itself in any noticeable symptom. The Kidney Foundation strongly recommends people get tested, especially when they have diabetes, obesity, cardiovascular disease, or an autoimmune disease.

Betsy Wilson

A true science nerd and pediatric nursing specialist, Betsy is passionate about all things pregnancy and baby-related. She contributes her expertise to the Scientific Origin.