Signs of Kidney Problems
Written by Ada’s Medical Knowledge Team
What is a kidney problem?
The kidneys form part of the urinary system, one of the body’s major filtration systems. Most people have two kidneys, situated in the upper abdominal area towards the muscles of the back and the edge of the ribs. The kidneys form part of the urinary system along with the two ureters, the bladder and urethra. Kidney problems affect the kidneys, but because the system works together, the effects of a kidney problem are sometimes felt throughout the system.
The kidneys themselves clean the blood by filtering it in the nephrons, which are made up of a renal tubule and a renal corpuscle. The corpuscle is made up of a glomerulus enclosed by the Bowman’s capsule. To filter the blood, it is passed through the glomeruli at higher pressure than the body’s usual blood pressure. Filtered waste products collect inside the Bowman’s capsule, while filtered, clean blood is passed back out of the glomeruli into the circulatory system.
The tubule collects the waste products from the Bowman’s capsule while also working on further exchanging certain substances and also reabsorbing water and certain minerals so they don’t go to waste. The final resulting liquid is then passed into the ureters as urine. Urine collects in the bladder, which stores it until it is released by the urethra.
Kidney problems in adults and teenagers are usually uncomfortable, but can typically be treated relatively easily by doctors. Kidney problems in pregnant women are of particular concern because of the effect they can have on both the pregnant woman and the baby. Diagnosing kidney problems in babies and toddlers can be difficult because their kidneys and bodies are relatively smaller and often cannot explain to their caregivers how they are feeling or where they are hurting.
General signs of kidney problems
- Urinating frequently and/or urgently
- Pain or burning while urinating
- Pus in the urine
- Cloudy or bad-smelling urine
- Foamy, frothy or bubbly urine
- Pink, red or brown urine
- Back pain, flank pain and/or groin pain
Foamy urine is a sign of proteinuria, which is often also accompanied by swelling in the hands, feet, abdomen and/or face. Proteinuria is a symptom of nephrotic syndrome (see below).
Pink, red or brown urine is a sign of visible blood in the urine, known as gross hematuria, which is a symptom of nephritic syndrome (see below). This condition requires medical treatment, and the affected person should seek medical assistance.
In addition, other kidney problems that are not infections, such as nephrotic syndrome, can also present with symptoms such as:
- Edema or puffiness in the face, abdomen or legs
- Weight gain due to fluid retention
- Unexplained weight loss
Concerned that you may have a kidney problem? Ada is ready to start your symptom assessment.
Signs of common kidney problems
Chronic kidney disease and COVID-19
People with chronic kidney disease are at risk of severe symptoms due to COVID-19. On the other hand, COVID-19 can also induce kidney disease in some cases.
Read more about the link between COVID-19 and chronic kidney disease here.
Signs of acute pyelonephritis
Acute pyelonephritis is a painful bacterial infection of the kidneys which occurs when bacteria enter the urethra, move into the bladder, travel up the ureters and affect the kidneys. It is usually caused by the bacterium Escherichia coli, but can sometimes be caused by other bacteria. 2
Acute pyelonephritis is a common kidney problem in females, especially those between the ages of 15 and 29. The condition is rare among males, although it is more common in men over the age of 65 or men with anatomical abnormalities of the urinary tract. 2 It can, however, affect people of any age. Although it is quite uncomfortable, acute pyelonephritis is seldom a cause of long term kidney problems. Some underlying conditions can increase the risk of developing acute pyelonephritis. These include: ref2
- Enlarged prostate / benign prostatic hyperplasia (BPH)
- States of immunosuppression, le.g. after receiving a transplant or in HIV-patients
- Recent acute kidney injury
The most distinctive features of acute pyelonephritis are lower back pain, pain in the side, along the lower ribs or lower abdomen, a fever of 38 degrees Celsius / 100.4 degrees Fahrenheit or more, chills, nausea and vomiting. Other symptoms of acute pyelonephritis include: 3 4
- Pungent or unpleasant-smelling urine
- Blood in the urine, also known as hematuria
- Urinating frequently and/or urgently
- Urinating painfully or with difficulty
- Producing no urine
- Low blood pressure, which can manifest as dizziness and/or faintness
- Jumbled speech
Good to know: As many as half of all people aged 75 and over may have some degree of chronic kidney problem. 5 In most cases, the kidney problem is not the result of an actual disease, but is instead the result of normal ageing. Most cases are mild or moderate, not severe. However, if an older person shows symptoms of a kidney problem they should see a doctor to have their kidney function assessed. For more information on the signs of age-related chronic kidney disease, see the section below.
Good to know: In babies and toddlers, the only sign of acute pyelonephritis may be a high fever.
Signs of nephritic syndrome
Nephritic syndrome is the name given to a collection of signs and symptoms that occur when the kidneys are inflamed. The syndrome is usually the result of an underlying condition such as acute glomerulonephritis, a bacterial or viral infection, a systemic disorder such as systemic lupus erythematosus, or a hereditary disorder like Alport-Syndrome. 6 7 A syndrome is a group of symptoms that often and typically occur together and often develop as a result of another condition.
Nephritic syndrome causes the kidneys to be less efficient at filtering waste substances from the blood. In people with nephritic syndrome, protein and blood may be found in the urine. However, most cases of nephritic syndrome are chronic and have few symptoms. Acute nephritic syndrome usually does, however, present with symptoms.
Typical symptoms of acute nephritic syndrome include passing less urine than normal, having blood in the urine and swelling of the feet or face (edema). Other possible symptoms of nephritic syndrome, also depending on the root cause may include: 6 7 8
- Pain in the back and/or sides
- Shortness of breath
- Symptoms related to the underlying cause, for example a rash or joint pain
The symptoms of nephritic syndrome differ, depending on whether the acute or chronic form of the syndrome is being experienced.
- Edema in the face and legs
- Low production of urine
- Blood in the urine
- Hypertension/high blood pressure
- Weakness and fatigue
- Loss of appetite
- Nausea and/or Vomiting
- Pain in the stomach
- Malaise (a feeling of general unwellness)
Chronic nephritic syndrome usually presents with fairly mild or even undetected symptoms, which can include: 8
Chronic nephritic syndrome may lead to kidney failure in its later stages.
In both chronic and acute nephritic syndrome, the urine will usually contain red blood cells or parts thereof, as the blood cells leak out of the damaged glomeruli. Urine does not usually contain red blood cells or the remains of red blood cells.
Signs of nephrotic syndrome
Nephrotic syndrome is a syndrome that indicates that there is a problem with the kidneys which leads to the person losing substantial amounts of protein via their urine.It can affect people of any age, but is most often the source of kidney problems in toddlers, children and teenagers. A syndrome is a group of symptoms that often occur together and develop as a result of another condition.
In children, this kidney problem is usually caused by a kidney disorder known as minimal change disease. More boys than girls are affected, and most children will experience the condition between the ages of 18 months and four years. 9
In adults, nephrotic syndrome is often caused by 2 kidney conditions that are associated with e.g. diabetes, autoimmune disorders such as systemic lupus erythematosus, or infections such as Hepatitis B or C, or HIV infection. Furthermore, severe preeclampsia is a cause of nephrotic syndrome in pregnant women.
- Loss of appetite
- Malaise and fatigue
- Frothy urine
- Edema or puffiness anywhere in the body, but especially around the eyes
- High cholesterol
- High blood pressure
- Hypoalbuminemia, low levels of the protein albumin in the blood
- Albuminuria, high levels of albumin in the urine
Proteinuria and edema are the two most distinctive symptoms of nephrotic disorder. Edema, particularly around the eyes, is one of the first visible signs of nephrotic syndrome.
Signs of chronic kidney disease
Chronic kidney disease (CKD) is generally without symptoms and painless in its early stages, except in situations where an underlying condition causes pain. Chronic kidney disease takes a long time to develop. If the affected person’s symptoms develop over a number of hours or a few days, it is more likely that the kidney problem they are experiencing is acute kidney injury (see below). 5
Chronic kidney disease is a common disorder, with an estimated 1 in 10 people in the US having some degree of the disorder. Chronic kidney disease can occur at any age, but is more common in the elderly, and it is more common in women than in men. In the elderly, CKD is often a result of ageing rather than an underlying disorder. 5
A diagnosis of chronic kidney disease is often made only in the later stages of the disorder. In the early stages, the disorder may not cause disturbances that can be clinically measured. Symptoms only appear later, and once they do, 12 the affected person will be tested by a physician to confirm that CKD is present.
- Neoplasms/Tumor growth
- Multisystem diseases such as systemic lupus erythematosus
- Polycystic kidney disease
- Frequent urinary tract infections
- Renal artery stenosis
- Blockages to the flow of urine, from obstructions of the urinary outflow tracts, i.e. the ureter and urethra
Other factors that can increase the likelihood of chronic kidney disease developing are:
- Overuse or long-term use of NSAIDs such as ibuprofen, high dose aspirin and naproxen
- A family history of hereditary kidney disease
Signs of later chronic kidney disease
- Weight loss
- Dry, itchy skin
- Poor appetite
- Fatigue and weakness
- A general feeling of unwellness
- Muscular cramps
- Frequent or urgent urination, especially at night
- Fluid retention in the lower limbs and feet
- Pulmonary edema
- Puffiness around the eyes and in the face
- Foggy thinking
- Trouble sleeping
- Restless legs
In the later stages, other symptoms may arise, including: 12
- Pleuritis, inflammation of the tissues lining the lungs and chest cavity
- pigmented spots
- Difficulty staying awake
- Peripheral neuropathy, causing numbness and tingling in the extremities
- Platelet malfunction and abnormal bleeding
- Decreased libido and, in men, erectile dysfunction
- Reduced ability to exercise or complete normal activities
- Confusion and foggy thinking
- Impaired immune function leading to getting sick more easily
Chronic kidney disease may, if not treated and managed adequately, result in acute kidney failure. Symptoms of acute kidney failure include: 14
- Stomach and/or back pain
If these symptoms appear, seek medical assistance as soon as possible. Seek emergency help if you experience problems with breathing or pain in your chest area, can’t stay awake despite trying or can’t keep fluids down at all.
For more information on chronic kidney disease, read this resource on chronic renal failure.
Signs of acute kidney injury
Acute kidney injury is a rapid or abrupt decline in kidney function and is considered a medical emergency. It occurs when there is direct injury to one or both kidneys, a blockage in the ureter or another condition causing insufficient blood flow to the kidneys.
- Low blood pressure that occurs very suddenly and/or is severely low
- Severe burns
- Severe diarrhea
- Severe allergic reactions
- Heart attack
- Liver failure
- Coronary artery disease or chronic heart failure
Some medications, such as diuretics, aminoglycoside antibiotics and some blood pressure pills can also cause acute kidney failure. Older people, as well as people with underlying conditions such as diabetes, liver disease or heart disease, are at increased risk.
In children, kidney failure can be caused by: 15
- Severe diarrhea
- Severe infection
- Blood-cell cancer
- Hypotension (low blood pressure)
Good to know: People, such as the elderly, the disabled and children, who are reliant on caregivers for a supply of fluids are at particular risk of dehydration. 15
- Passing less urine than usual
- Nausea and vomiting
- Poor appetite
- Swelling in the legs, abdomen or face.
- Lethargy and/or trouble staying awake
- Asterixis, a kind of involuntary shaking of the hands
- Tenderness of the abdomen
- Tenderness or pain in the area of the the lower ribs
Signs of kidney problems during pregnancy
Preeclampsia affects only pregnant women after the 20th week of pregnancy and resolves shortly after the baby is delivered. Although it is by origin not a primary kidney problem, it does involve the kidneys. It is characterised by: 17
- Proteinuria, or protein in the urine
- Headache that cannot be alleviated with painkillers
- Edema (swelling) of hands, arms, face and/or feet
- Blurred vision, other visual disturbances or blind spots
- Confusion or disorientation
- Nausea and vomiting
- Pain in the upper right abdomen, just below the ribs
- Heartburn that cannot be alleviated by antacids
- Feeling of great unwellness
- Oliguria (low urine output) of 500ml or less over 24 hours
- Being unable to feel the baby move as much as previously
- Shortness of breath, possibly due to pulmonary edema (excess fluid in the lungs)
- Stroke. This is very rare
Good to know: If a pregnant person suddenly discovers that their watch, bracelets or rings no longer fit their arm or hand, or that their sleeves are suddenly tight, they should seek medical help immediately. Preeclampsia can lead to eclampsia and HELLP Syndrome and is considered a medical emergency.
For more information on, see this resource on preeclampsia, eclampsia and HELLP Syndrome.
If you are concerned that you or a loved one may have preeclampsia, eclampsia or HELLP Syndrome, download the Ada app for a free symptom assessment.
Kidney stones or nephrolithiasis
Kidney stones are normally made up of hard collections of minerals which form in the renal system. These stones may stay in the kidneys for quite a while. They often become painful when they move out of the kidney into the ureter. The pain is often described as a strong colicky pain, usually felt in the ureter between the kidney and the bladder. Kidney stones can be extremely painful.
Colicky, strong to very strong pain coming in waves, is the most obvious symptoms of kidney stones. The location of the pain and where it spreads to gives clues as to where the stone is currently located in the urinary system. The pain of a kidney stone passing through the urinary system is felt suddenly and severely in the flank (the side) and spreads down the groin on the same side. Not all stones cause radiating pain. Some stones may not cause any pain.
Good to know: Pain from kidney stones is often described as excruciating. Kidney pain from kidney stones can come and go. It can occur in bouts lasting between 20 minutes and an hour. People with painful kidney stones often cannot keep still because of the discomfort. They are often pale and sweaty, with a painful, tender abdomen. 21
- Painful urination, as well as having to urinate frequently and very urgently or uncontrollably
- Hematuria, visible blood in the urine
- Cloudy and/or bad-smelling urine
- Inability to urinate because of blockage in the ureter
- Gravel or stone-like particles in the urine
For more information, read this resource on kidney stones.
If you are concerned that you might have kidney stones, or nephrolithiasis, consult the Ada app for a symptom assessment.