Kidney Disease FAQ

What are the first signs of kidney disease?

Clinicians usually find out about kidney diseases during blood or urine tests.1 It is hard to detect the early stages of chronic kidney disease due to homeostasis. However, patients with acute or later stages of renal diseases may experience:

  • Blood in urine: a sign of disrupted filtering functions of the kidneys. Healthy kidneys have filters called glomeruli which keep red blood cells in the blood vessels rather than entering the urinary tract. Blood in the urine may be an early sign of glomerulonephritis
  • Foamy urine: may be an indication of chronic kidney diseases due to tubular or glomerular dysfunctions. Proteins are large particles that cannot cross the glomerular filtration barriers. Relatively smaller albumin particles may pass the barrier, but tubular reabsorption would take the molecules back into the blood.2 When the functions are disrupted, protein enters the kidneys and would not removed from the urine during reabsorption. A high concentration of protein in the urine is termed nephrotic syndrome.
  • Polyuria (urinating more than usual): indicates that water molecules are not efficiently reabsorbed into the blood vessels. The urine concentration is low, and the patients urinate more frequently, especially at night. 
  • Lower back pain

Other clinical features, including anemia, nausea, lowered immunity against infections, and infertility, may also occur later in chronic kidney disease.1,3

What are the most common kidney diseases?

The three main categories of kidney diseases are nephritis, acute renal failure (ARF), and chronic kidney disease (CKD). Nephritis can lead to both acute and chronic renal diseases.

Kidney infections and inflammation define nephritis. The type of nephritis depends on the region of the inflammation. For instance, glomerulonephritis indicates damage in glomeruli (the “ball” shaped filters in the kidney); bacterial infections in the urinary tract cause pyelonephritis; and interstitial nephritis occurs between the tubules in the kidneys, mostly caused by allergic reactions to drugs. Nephritis can either be acute or chronic, depending on the length and frequency of inflammation. 

Acute renal failure is defined by a sudden glomerular filtration rate (GFR) drop and a persistent increase in urea and creatinine concentration. The condition develops rapidly and can be fatal. The causes can be categorised into pre-renal, intrinsic renal, and post-renal causes, of which vascular diseases, nephritis, and tubular injuries are the most common triggers.

Other than being caused by recurrent/long-term renal damage, chronic kidney disease can also be triggered by other chronic conditions, such as diabetes, high blood pressure, and high-fat levels. There are five stages of the disease, and the condition can rarely be diagnosed during early stages, as most patients are asymptomatic until the GFR falls below 15 ml/min (whilst normal GFR is over 90 ml/min). However, patients can prevent the condition by adopting healthy living habits and controlling other age-related diseases due to their slow development.1 

What should I know about kidney disease?

Renal function is linked with multiple organs and body functions via the blood, including fertility, blood pressure, blood glucose, protein level regulations, etc. Defects in renal functions are, therefore, a typical complication of other diseases.5 Multiple other diseases, such as high blood pressure and diabetes, can cause kidney disease. As a result, the severity of the disease can be regulated by monitoring the risk factors.6 

Kidney disease can also lead to other conditions. For example, when CKD occurs, the decreased GFR would trigger the rise of aldosterone concentration.7 This may lead to hyperaldosteronism when the adrenal function is also impaired. An excess amount of aldosterone would impair the kidneys’ ability to reabsorb water by creating a high salt concentration, it also overloads the kidneys’ filtration system with potassium, further damaging the system. Due to the high blood concentration and lack of water, high blood pressure could be induced.8,9,10,11

What foods help your kidneys recover?

Foods with low sodium levels can help recover your kidney functions by repairing the water reabsorption from the kidneys to blood vessels, increasing the GFR. As the reduction of GFR is associated with high fat and salt levels, it is important to monitor your diet and select foods such as green-leaved vegetables and fruits rather than high-fat meat, cheese, smoked food, pickles, etc. Fat that is relatively healthy such as milk, olive oil, and fish, can be consumed by patients with kidney diseases. The DASH eating plan is recommended for people with hypertension and those with kidney diseases. 

Can you get kidney disease at any age?

Yes, you can get kidney disease at any age, despite the fact that older age groups are more likely to develop the condition. The chance of people developing ARF peaks amongst people aged 70-79, and those over 65 have a higher chance of developing CKD than younger people.12,13 This is due to a higher risk of developing cardiovascular diseases and metabolic disorders amongst older people, which impacts the GFR of the kidneys. 

Is alcoholic kidney disease reversible?

Heavy drinking may lead to permanent damage to kidney functions. However, quitting drinking would slow down the damage to your kidneys if you have been diagnosed with chronic alcoholic kidney disease. 

As alcohol contains high energy levels and may cause increased blood pressure and cholesterol, it may worsen the condition if the patients also experience renal disease.1 Excessive drinking/binge drinking may directly cause acute renal failure or end-stage renal disease (ESRD) in chronic conditions.14 Kidneys would no longer function due to the system overload, and only treatments such as kidney transplantation could support the patients survival. 

What is the best medicine for kidney disease?

Currently, the most effective medications for kidney disease are ACE inhibitors and ARBs, which may effectively repair the GFR and treat CKD. They are also widely used to treat high blood pressure, as they help relax the blood vessels. However, these drugs can produce side effects such as excessive potassium in the blood; and may lead to heart failure if the dosage is not controlled.15,16 None of these drugs can treat severe CKD from stages 3-5. 

Why are kidney problems serious?

Our kidneys function as one of the main sites to filter out toxins. The removal of waste and the balance of blood electrolyte and hormone concentrations depend on renal function. When the kidneys stop functioning, toxic substances accumulate in the blood vessels, and essential hormones cannot be produced or activated for normal body functions. The imbalanced electrolyte concentration in the blood also promotes the development of pathologies such as hypertension and peripheral neuropathy.17,18  These diseases heavily impact our hearts and brains and may increase mortality.. 

Is kidney disease fatal?

Early stages of chronic kidney disease can be treated and easily controlled by adopting healthy lifestyles. However, both acute and chronic kidney diseases can be fatal, as they may trigger other severe health conditions. Both acute and chronic conditions have different levels of severity. 

Although acute renal failure progresses more rapidly, chronic kidney disease is unlikely to be diagnosed until the condition becomes severe. Urgent treatment, including dialysis and kidney transplantation, is needed for both acute and end-stage renal failure, to ensure the survival of patients.1,19


  1. NHS Choices. Symptoms - Chronic kidney disease [Internet]. NHS. 2019. Available from:
  2. ‌Gorriz JL, Martinez-Castelao A. Proteinuria: detection and role in native renal disease progression. Transplantation Reviews [Internet]. 2012 Jan 1;26(1):3–13. Available from:
  3. ‌Anemia in Chronic Kidney Disease | NIDDK [Internet]. National Institute of Diabetes and Digestive and Kidney Diseases. Available from:
  4. Makris K, Spanou L. Acute Kidney Injury: Definition, Pathophysiology and Clinical Phenotypes. The Clinical biochemist Reviews [Internet]. 2016 May;37(2):85–98. Available from:
  5. NIDDK. Your Kidneys & How They Work | NIDDK [Internet]. National Institute of Diabetes and Digestive and Kidney Diseases. 2018. Available from:
  6. NIDDK. Causes of Chronic Kidney Disease | NIDDK [Internet]. National Institute of Diabetes and Digestive and Kidney Diseases. 2016. Available from:
  7. Hannemann A, Rettig R, Dittmann K, Völzke H, Endlich K, Nauck M, et al. Aldosterone and glomerular filtration – observations in the general population. BMC Nephrology [Internet]. 2014 Mar 10 [cited 2022 Sep 8];15(1). Available from:
  8. ‌Piccoli GB, Capobianco M, Odetto L, Deagostini MC, Consiglio V, Radeschi G. Acute renal failure, severe sodium and potassium imbalance and sudden tetraplegia. Clinical Kidney Journal [Internet]. 2010 Mar 19;3(3):247–52. Available from:
  9. Borrelli S, Provenzano M, Gagliardi I, Ashour M, Liberti ME, De Nicola L, et al. Sodium Intake and Chronic Kidney Disease. International Journal of Molecular Sciences. 2020 Jul 3;21(13):4744.
  10. What is the link between kidney disease and potassium? [Internet]. 2021. Available from:
  11. ‌Wein H. How the body regulates salt levels [Internet]. National Institutes of Health (NIH). 2017. Available from:
  12. Coca SG. Acute Kidney Injury in Elderly Persons. American journal of kidney diseases : the official journal of the National Kidney Foundation [Internet]. 2010 Jul 1;56(1):122–31. Available from:
  13. ‌CDC. Chronic Kidney Disease in the United States, 2021 [Internet]. 2021. Available from:
  14. National Kidney Foundation. Drinking Alcohol Affects Your Kidneys [Internet]. National Kidney Foundation. 2017. Available from:
  15. Heran BS, Wong MM, Heran IK, Wright JM. Blood pressure lowering efficacy of angiotensin receptor blockers for primary hypertension. Cochrane Database of Systematic Reviews. 2008 Oct 8;
  16. Herman LL, Bashir K. Angiotensin Converting Enzyme Inhibitors (ACEI) [Internet]. StatPearls Publishing; 2019. Available from:
  17. Kidney Research UK. The Kidneys -a Basic Guide [Internet]. 2006. Available from:
  18. ‌Arnold R, Issar T, Krishnan AV, Pussell BA. Neurological complications in chronic kidney disease. JRSM Cardiovascular Disease [Internet]. 2016 Mar 21;5:204800401667768. Available from:
  19. NHS. Acute Kidney Injury [Internet]. NHS. 2019. Available from:

Yongyi Dai

Master of Science – MSc Translational Neuroscience, Imperial College London, United Kingdom

Daisy (Yongyi) is a student, currently undertaking a master’s degree in Translational Neuroscience. She aims to study and research effective gene therapies to treat neurodegenerative diseases, such as Alzheimer’s disease.

She has completed individual research projects, including “How does age affect our cooperation?” and “Composing a piece of music to aid children with autism.” She led the Sing-Along Surrey project at Royal Holloway University of London between 2020 and 2021 to connect students with residents in local care homes; and she fundraised for charities including Dementia UK and Children’s Hospice South West. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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