Early Stages Before Kidney Failure

Chronic kidney disease is a largely irreversible, long-term disease characterized by the gradual loss of kidney function over months or years. Stages 1, 2, and 3 are considered the early stages, during which you may have few, if any, symptoms. The loss of kidney function is indicated by the CKD stage and based on the results of an eGFR test.

Stage 1 CKD

Stage 1 CKD is when there is some kidney damage but eGFR is still in the normal range (90 and above). The diagnosis is made when a test called an albumin/creatinine ratio (ACR) shows the excessive loss of a protein called albumin in your urine.

Stage 1 CKD rarely causes notable symptoms. Even so, steps would be taken to preserve kidney function. Key to this is managing hypertension (high blood pressure) and diabetes which account for up to 51% and 66% of CKD cases, respectively.

Recommended interventions include:

Stage 2 CKD

Stage 2 CKD occurs when you have mild kidney damage and your eGFR has dropped to between 60 and 89. However, your kidneys can still filter blood, and your risk of symptoms remains low.

If symptoms occur, they tend to be nonspecific, meaning they could be due to several other conditions:

Although the treatment recommendations differ little from stage 1 CKD, greater effort is placed on keeping your blood pressure below 120 millimeters of mercury (mm Hg) and your fasting blood sugar below 100 milligrams per deciliter (mg/dL). You would also be advised to quit cigarettes if you are a smoker.

Stage 3 CKD

Stage 3 CKD is when your kidneys have sustained mild to moderate damage and your eGFR has decreased to between 30 and 59.

Stage 3 is further divided into these two substages:

• Stage 3a: eGFR between 45 and 59
• Stage 3b: eGFR between 30 and 44

These substages are designated by different clinical patterns and different risks of death. With stage 3b, a person is more likely to experience overt signs of kidney disease and would typically be referred to a nephrologist.

Even at stage 3, many people with CKD remain entirely asymptomatic (without symptoms). But for those who progress to stage 3b and edge closer to stage 4, the buildup of wastes can start to adversely affect the heart, bones, blood, muscles, and nervous system.

In addition to foamy urine and other early signs of CKD, a person with stage 3 disease may also experience:

• Fatigue (caused in part by a drop in blood iron and the onset of anemia)
• Insomnia and sleep disruptions
• Kidney pain (generally a dull ache felt in the lower back)
• Restless leg syndrome (RLS) (neurological disorder causing uncomfortable feelings in the legs)
• Swollen hands or feet (caused by fluid retention, also known as peripheral edema)

The treatment of stage 3 CKD expands upon that used in stages 1 and 2 and would generally include:

• Reducing protein intake to between 0.6 and 0.75 grams/kg of your body weight
• Consuming under 2,000 milligrams (mg) of sodium per day
• Calcium and vitamin D supplements
• Iron supplements to treat anemia
• Diuretics (“water pills”) to promote urination and reduce fluid retention

Even in the absence of diabetes, SGLT2 inhibitors may be prescribed for people with stage 3b CKD. Studies have shown that these drugs may reduce the risk of kidney failure and death by 40%.

Progression to the Final Stage of Kidney Failure

Stages 4 and 5 are considered the later, more advanced stages of CKD. During these stages, more aggressive interventions are needed to avoid kidney failure (end-stage renal disease or ESRD).

Stage 4 CKD

Stage 4 CKD is when you have moderate to severe kidney damage and an eGFR between 15 and 29. At this stage, your kidneys are close to not working, and will likely experience more unmistakable signs and symptoms.

Symptoms develop when failing kidneys can’t clear potassium from the blood, leading to a toxic accumulation known as hyperkalemia. Symptoms of hyperkalemia include fatigue, weakness, muscle cramps, nausea or vomiting, shortness of breath, and heart palpitations.

Similarly, excessive phosphorus (hyperphosphatemia) can start to draw calcium from bones and affect muscle and nerve function. Symptoms of hyperphosphatemia include itching, rash, numbness, bone and joint pain, muscle spasms, and pins-and-needles sensations.

The transition from stage 3 to stage 4 is considered the point at which kidney damage is so significant that permanent and aggressive interventions are needed to avoid illness and death.

In addition to the standard treatments used for stages 1 through 3, interventions would be needed, including:

• Limiting protein intake to 0.6 gm/kg of body weight per day
• Restricting phosphorus intake to 800 to 1,000 mg per day
• Restricting potassium intake to 2,000 to 3,000 mg per day
• Taking erythropoiesis-stimulating agents (ESAs) to treat severe anemia

With strict adherence to treatment, a person with stage 4 CKD may not progress to stage 5.

Stage 5 CKD

Stage 5 is the most advanced stage of CKD where a person either has or is about to experience kidney failure. When the eGFR drops below 15, symptoms are generally extreme and typically include:

• Headaches
• Extreme fatigue and weakness
• Significant peripheral edema affecting the hands, feet, arms, and legs
• Persistent lower back pain
• Changes in skin color
• Muscle cramps, sometimes severe
• Loss of appetite
• Nausea and vomiting

At stage 5, you would either need to undergo dialysis (the mechanical filtering of your blood) or have a kidney transplant in order to survive.

Other interventions may be needed, including drugs called phosphate binders that prevent your body from absorbing phosphorus from the foods you eat. Fluid restriction combined with low sodium intake would also be needed to prevent fluid retention.

End-Stage Kidney Failure

End-stage renal disease, also known as end-stage kidney failure, is when the function of your kidneys is so diminished that they are no longer able to sustain life.

Without treatment, wastes and toxins will rapidly accumulate in the blood (uremia). Depending on how rapidly toxins build, a person will undergo extreme and worsening symptoms such as:

Left untreated, death from end-stage renal disease usually occurs within days or weeks.

Dialysis

Dialysis is usually the first treatment option for ESRD and may be the only option. Nearly three of every five people with ESRD have a contraindication for a kidney transplant.

The two main types of dialysis are:

• Hemodialysis uses a special machine that mechanically removes, filters, and returns your blood to active circulation.
• Peritoneal dialysis involves the introduction of a filtering solution into your abdomen, which draws toxins and wastes from the lining of your abdomen, and then draining the fluid.

Even with dialysis, dietary restrictions need to be adhered to.

Kidney Transplant

Although dialysis can help manage the symptoms of ESRD over the long term, a kidney transplant remains the preferred treatment option. A transplant offers longer life expectancy, fewer dietary restrictions, a higher quality of life, and a lower risk of complications.

Referral to a kidney transplant program generally starts when a person is diagnosed with stage 4 CKD. The median wait time for a kidney transplant in the United States is four years.

Palliative Care

Palliative care focuses on alleviating pain, stress, and other symptoms while undergoing medical treatment. It is delivered by a specialized team of providers who aim to improve the quality of life of individuals with CKD as well as those of their families.

Palliative care for ESRD may involve:

• Pain management
• Management of comorbidities like hypertension, heart disease, and diabetes
• Coordination of care among multiple healthcare providers
• Assistance with critical decisions, such as dialysis and kidney transplant
• Emotional and spiritual support
• Stress management

If someone with ESRD decides to forego or discontinue dialysis and is not a candidate for a kidney transplant, palliative care may be transitioned to hospice care. With hospice care, quality of life is emphasized over the extension of life, and curative treatment is not pursued.

Disease Progression and Prognosis

Not everyone with CKD will experience progression, particularly if the appropriate preventive steps are taken. However, people who fail to control their blood pressure or blood sugar will commonly see a steady decline in their eGFR. This increases the risk of stages 4 and 5 CKD.

Current research states:

• For people with CKD and hypertension, progression from stage 1 to stage 2 generally takes seven years and another seven years to progress to stage 3. Unless blood pressure is controlled, progression from stage 3 to stages 4 and 5 usually occurs within 10 years.
• People newly diagnosed with type 2 diabetes will usually develop CKD within 10 to 20 years. If the blood sugar is not adequately controlled, CKD can progress to stage 3b within 13 years and stages 4 and 5 within 19 years.

Life Expectancy

Only around 2% of people with CKD progress to end-stage renal disease, most often after the age of 65. (This seemingly low rate is due to the fact that people with advanced CKD tend to die of comorbid conditions, like heart disease before the kidneys start to fail).

If ESRD is diagnosed, dialysis or a kidney transplant can dramatically extend life expectancy. Based on current research:

• With dialysis, the average life expectancy for someone with ESRD is between five and 10 years, although some people have been known to live for as long as 30 years.
• With a kidney transplant, the average life expectancy is between 20 and 25 years if the kidney is from a living donor and 15 to 20 years if the kidney is from a deceased donor.

Summary

Chronic kidney disease (CKD) progresses in five stages. Stages 1, 2, and 3 are considered the early stages of CKD when symptoms are often absent. Stages 4 and 5 are the advanced stages when kidney damage can cause severe symptoms and lead to kidney failure.

With lifestyle changes, dietary management, and medications, CKD progression can be slowed or altogether stopped. If CKD is allowed to progress and kidney failure occurs, dialysis and a kidney transplant are the only treatment options.