Types of acute and chronic kidney disease

Overview of the acute and chronic kidney disease

The human body has two kidneys – acute and chronic kidney; each has a size nearly equal to the size of a fist. They are present near the middle of the back, just immediately below the rib cage. Each kidney contains millions of tiny structures known as nephrons. They help in the blood filtration of the body. It helps in removing all extra metabolic waste byproducts like excess water, salts, minerals, and other toxic substances via urine. Urine is produced by the kidneys as a waste material of the body which contains all toxins and flows through the tubes known as ureters and reaches the urinary bladder. Urinary bladder helps in storing the urine until it is passed out of the body when one goes to the bathroom.

In all the kidney diseases nephrons being the smallest units of the renal system are the center of attack. It damages the ability of the kidneys to remove metabolic wastes from the body. Its cause can either be some hereditary disease or any injury or long-term medication therapy. A person is more prone to kidney diseases if there is any history of diabetes, blood pressure or even family history of kidney diseases. The kidney disease is mainly classified as an acute or chronic disease. It eventually causes loss of ability to concentrate or dilute tubular filtrate and removal of nitrogenous wastes and acid-base maintenance in the body.


What are the types of acute kidney disease?


Acute kidney disease or acute kidney injury (AKI) is also termed as acute kidney failure. In this kidney disease deterioration of the kidney functioning occurs in few hours to just a couple of days. This sudden shut down of kidney systems leads to failure in nitrogenous waste excretion from the body. Further fluid imbalance, electrolyte and acid-base imbalances in the body since these are all controlled by the kidney itself. Acute kidney disease can be reversed if diagnosed early and proper treatment is provided. Otherwise further worsening of the kidney might lead to chronic kidney disease and complete failure of the renal system of the body. Acute kidney disease can be caused by:

  1. Decreased renal perfusion:

Dehydration can lead to a hypovolemic condition which might cause a reduction in renal perfusion and it further can trigger the AKI.


  1. Intrinsic renal disease:

It might occur because of a nephrosis condition or any infection or inflammation due to nephritis in the renal system.


  • Nephrosis:

    Any trauma, ischemia or any toxic injury might lead to acute tubular necrosis. Amongst all ischemia is one the most common reason for acute renal failure. It can be because of some prerenal conditions like dehydration and hypovolemia. Usually, ischemia triggered acute tubular necrosis is reversible if the underlying cause (like vessel injury or extensive necrosis) is found and treated.


  • Nephritis:

    Nephritic renal failure is probably because of either any vascular compression or by vasculitis. It is, triggered by rocky mountain, ehrlichiosis, leptospirosis, and bacteremia.

chronic kidney


  1. Post-renal causes:

This happens mainly because of any outflow obstruction or rupturing of the vessels inside the renal system.


What are the types of chronic kidney disease?


Chronic kidney disease is generally due to slow gradual progression of the disease. It causes the chronic deterioration of functioning of the kidney. It is sometimes, followed by the acute kidney injury or disease. Chronic kidney disease involves the following four stages while it progresses:

Stage 1 Involves decreased renal reserve:

In this stage of kidney disease, there appears a gradual increase in the creatinine and urea levels which however appears in the specified reference levels.  There are sometimes less clinical data to reveal the comparative less functioning of the kidneys. However, the reality of this stage is that the kidneys are potentially less capable to compensate dehydration in the body and perfusion also decreases.


Stage 2 Involves chronic renal insufficiency:

Moving to the next level of deterioration, the kidney function decreases further in this stage. It leads to a loss in the ability of urine to concentrate and even polyuria which further ends in azotemia (level of nitrogenous compounds like urea and creatinine increases in the blood). However, a clinical sign of uremia still takes time to appear in the lab results.


Stage 3 Involves chronic renal failure:

Clinical data depicts the presence of uremia clearly in this stage of kidney disease. Further worsening of azotemia occurs with the progression of the disease. And there are chances of developing any additional abnormalities like of metabolic acidosis during this disease stage.


Stage 4 Involves end-stage renal disease:

In this stage, the kidney is unable to produce much urine. It leads to oliguric condition and involves severe changes in the blood serum levels. It approaches a stage gradually where the entire functioning of the kidney fails and kidney is no longer able to eliminate any waste from the blood of the body and hence person has to go for either dialysis or a kidney transplant.

chronic kidney

In some patients with chronic renal failure, there are chances of an acute exacerbation of the kidney disease as well. Also, the causes for chronic renal failure (CRF) can be many like any inherited kidney disease, trigger this or it can be either glomerulonephritis or amyloidosis, or even both can co-exist and trigger CRF.


Differentiation of both acute renal failure and chronic renal disease can sometimes be difficult however disease history, several lab data and clinical signs might help in the clear diagnosis of the disease. After which a call upon the treatment, taken in order to cure the patient of this disease. Further reversal of AKI is still possible but reversal for CRF is not possible even after trying several lines of treatment. The damage done to the kidneys is to such an extent that it becomes impossible to reverse in case of CRF.

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