Chronic Kidney Disease

At a glance

The kidneys are the organs that filter waste and extra water out of the blood and send them out as urine.

Asan Medical Center describes chronic renal failure as
"a disease at a stage where the kidney function that removes waste has declined and cannot be restored to normal".

The important part here is "cannot be restored to normal".
Once a kidney is damaged, it cannot be turned back.

So the goal of treatment is not to cure it, but to slow down how fast it gets worse.
The earlier it is found, the more you can protect.

Causes — mostly diabetes and high blood pressure

This is the order of causes of chronic renal failure in adults given by Asan Medical Center.

1. Diabetes — recently it accounts for about 50%
2. High blood pressure
3. Glomerulonephritis
4. Polycystic kidney disease

If you have diabetes or high blood pressure, your kidneys already need care.
This is not something for later.

Diagnosis criteria

Asan Medical Center explains that when the glomerular filtration rate stays at or below 60% of normal for 3 months or longer,
it is diagnosed as chronic renal failure.

You can think of the 'glomerular filtration rate' as a score that shows how well your kidneys are filtering.
In English it is written as eGFR or GFR.

This number is often already printed on your national health screening (국가건강검진) result sheet.
How to read it is set out below in 'Checking your kidney status'.

This page is reference information that summarises official sources.
Always talk with a medical professional about diagnosis and treatment.

There are almost no symptoms early on

Asan Medical Center says that in the early stage of chronic renal failure there are almost no symptoms.

The kidneys give no sign until their function has dropped quite a lot.
So by the time people feel symptoms and go to hospital, it has often already progressed a long way.

This is a disease you have to find with numbers, not with symptoms.

Symptoms that appear as it progresses

These are the symptoms listed by Asan Medical Center.
The symptoms below usually appear only after it has already progressed a good deal.

• Swelling — the face and legs swell
• Tiredness, drowsiness — and problems with sensation and movement, and reduced consciousness
• Itching (pruritus) — the skin keeps itching for no clear reason
• Loss of appetite, nausea, vomiting
• Anemia, a tendency to bleed
• High blood pressure, arteriosclerosis
• Pulmonary edema, pleural effusion (fluid in and around the lungs) — you get short of breath

Check these signs

• When there is a lot of foam in your urine and it does not go away — this can be protein in the urine. A urine test confirms it
• When you wake up several times at night to urinate
• When your face or legs swell again and again
• When you keep itching for no reason

These symptoms can come from other causes too.
But if you have diabetes or high blood pressure and also have the symptoms above, do not put it off.

People who should check every year even without symptoms

• People with diabetes
• People with high blood pressure
• People with a family member who has kidney disease
• People who take painkillers or many medicines for a long time
• People aged 65 and over

People with diabetes are supposed to have a kidney test every year from the moment they are diagnosed.
Please also read the 'complication tests' part of Muromuro's [Diabetes] page.

If you have had the national health screening (국가건강검진), the answer is already on your result sheet.
Most people just skip past it, but this is where kidney disease can be found several years earlier.

Two boxes to look for on the result sheet

① Glomerular filtration rate (eGFR)
This is a score that shows how well your kidneys are filtering.
On the sheet it is written as '신사구체여과율', 'eGFR' or 'GFR'.

② Serum creatinine
This is the waste product that the kidneys have to filter out.
If this value is high, it means the kidneys are not filtering well.
Asan Medical Center lists this test as the most important test in diagnosis.

It is good to look at the protein in urine item of the urine test together with these.

Glomerular filtration rate stage table

These are the criteria of the Korean Society of Nephrology.

| Stage | Glomerular filtration rate | Condition |
|---|---|---|
| Stage 1 | 90 or above | Kidney function is normal |
| Stage 2 | 60~90 | Kidney function is starting to decline |
| Stage 3 | 30~59 | Kidney function has declined further |
| Stage 4 | 15~29 | Barely keeping the function needed to stay alive |
| Stage 5 | Under 15 | Hard to stay alive without dialysis or a transplant |

60 is the turning point

If it stays under 60 for 3 months or longer, it is treated as chronic kidney disease.

• 60 or above — if you have diabetes or high blood pressure, check every year
• It came out under 60 — do not just skip past it; go and see a doctor. One number does not confirm it, but it needs checking
• Under 30 — this is a stage that needs a nephrology visit

⚠️ The most common mistake
It is thinking, "60 is half, so I am still fine."
Kidneys cannot be turned back. Protecting them at 60 and
starting after they have fallen to 30 give completely different results.

Bring your result sheets

When you go to the hospital, bring last year's and the year before's result sheets too.
How it has changed over several years matters far more than one number.

If you have lost your screening result sheet,
you can check past screening results at the National Health Insurance Service (국민건강보험공단).

Where to go first

• Internal medicine — if a number was flagged at screening, you can start at a local internal medicine clinic
• Nephrology — this is the department that specializes in the kidneys. Look for a place with '신장내과' or '신장' on its sign

Nephrology is rare at neighbourhood clinics.
It is more often found at general hospitals and above.

When you should go to nephrology

• When your glomerular filtration rate is under 30
• When the number is falling quickly
• When protein in the urine keeps showing up
• When diabetic kidney disease is progressing
• When the cause is unknown

If you are not sure, ask at the internal medicine or diabetes clinic you already attend.
Say, "Is my condition one that needs a nephrology visit?" and they will judge for you.

Departments you may attend as well

• Endocrinology / internal medicine — diabetes care (it is the number one cause)
• Cardiology — blood pressure care
• Vascular surgery — surgery to make a blood vessel access when preparing for dialysis
• Transplant surgery / kidney transplant team — if you have a kidney transplant

Choosing a hospital to keep attending

Chronic kidney disease is a condition you live with for life.
But unlike diabetes and high blood pressure, once it has progressed a certain amount you need a hospital with a nephrology department.

• Early (stage 1~2) — managed at the internal medicine clinic you already attend, with a yearly check
• Middle stage onward (stage 3~) — a hospital with nephrology
• When dialysis is getting close — a hospital with a dialysis unit

If you go to a tertiary hospital as an outpatient, you need a referral letter (진료의뢰서) for national health insurance (건강보험) to apply.

You can look up neighbourhood clinics and large hospitals together on the map.

These are the tests listed by Asan Medical Center.

Basic tests

• Serum creatinine — the most important test. Blood is drawn to check the waste level
• Glomerular filtration rate (GFR) — calculated from the creatinine value and your age and sex. If it stays at or below 60% of normal for 3 months or longer, chronic renal failure is diagnosed
• Urine test (urinalysis) — checks whether there is protein or blood in the urine

Additional tests

• Ultrasound · CT — looks at the size and shape of the kidneys. Kidneys damaged over a long time are sometimes smaller
• Kidney biopsy (tissue test) — a piece of kidney tissue is taken to check, when the exact cause needs to be known

Things to know before testing

• The glomerular filtration rate is not confirmed from a single value. It is checked several times over time
• Hard exercise, dehydration, or eating a lot of meat can change the number
• Be sure to bring your earlier test records. The direction of change matters more than one number

Numbers you will keep seeing from now on

As you keep attending appointments, you will see these values again and again.
If you write them down, you can follow your own condition yourself.

• Glomerular filtration rate (eGFR)
• Creatinine
• Protein in urine (albuminuria)
• Blood pressure
• Hemoglobin (anemia)
• Potassium, phosphorus, calcium

Asan Medical Center explains treatment of chronic renal failure in four steps.

1. Treating the underlying disease

• Diabetes — blood sugar control
• High blood pressure — blood pressure control
• Treating other underlying diseases such as glomerulonephritis

If the cause is not controlled, the rest of the treatment is of no use.
Managing diabetes and high blood pressure is itself kidney treatment.

2. Slowing down how fast kidney function declines

Asan Medical Center says that "a low-salt, low-protein diet is important".

Salt (sodium)

"If you eat salty food, salt builds up in the body and the body swells more badly,
and even difficulty breathing can appear, so it must absolutely be avoided."

Protein
You should eat an appropriate amount.
Eating too much can bring on vomiting and weakness all over the body.

⚠️ Note: this does not mean cutting protein out completely.
If you eat none at all, you become undernourished and get worse instead.
Always get nutrition counselling about how much you should eat. Large hospitals and public health centers provide it.

Potassium
The advice is to blanch vegetables and to eat only a small amount of fruit.

3. Managing complications

Anemia, poor nutrition, bone disease and high blood lipids are treated together.
And you have to be careful with medicines that make kidney function worse.

When you go to another hospital, always say "my kidneys are not good."
Painkillers, contrast dye and some antibiotics put a load on the kidneys.

4. Renal replacement therapy

If it still progresses to the end stage despite all this treatment, you will have dialysis or a kidney transplant.
The details are in the next section.

Which treatment is used, and how, differs from person to person.
Discuss it fully with your medical team.

Even if this does not apply to you yet, it is good to know about in advance.
If you have to decide suddenly, you are short on both preparation and peace of mind.

When does it happen

According to the stage guidance of the Korean Society of Nephrology,
a glomerular filtration rate under 15 (stage 5) is a state where
it is hard to stay alive without dialysis or a transplant.

But the exact starting point is not decided by one number alone;
the medical team judges it together with your symptoms and your overall condition.

Two methods

Hemodialysis

• Usually done by going to a hospital (a dialysis unit)
• You have to attend the hospital regularly
• Surgery to make a blood vessel access in the arm is needed beforehand

Peritoneal dialysis

• A tube is placed in the abdomen and you do it at home
• You get training and then do it yourself

Which one is better depends on your lifestyle, age and physical condition.
Whether you have a job, how well you can move, and whether family can help are all considered.
You can choose after discussing it with your medical team.

Kidney transplant

You need a donor, and the conditions have to match.
After a transplant, you keep taking medicine that prevents rejection.

Things that help if you prepare early

• Have the blood vessel access surgery done in advance. Making it after dialysis has become urgent is hard
• You will be told not to have blood drawn or blood pressure measured on the arm where the access will be made
• Ask the hospital's social work team for counselling. They help you look at costs and support programs together
• If you have a job, discuss in advance how to fit the dialysis schedule around your work

Starting dialysis is not the end; it is carrying on with life in a different way.
Many people keep working. Knowing about it in advance makes it much less frightening.

The special cost-sharing program for serious illness (산정특례)

For chronic renal failure, if you start dialysis you may be eligible for the special cost-sharing program.
Once you are registered, the out-of-pocket cost rate for related care drops a lot.

The conditions and the period are set,
so check with the hospital administration desk (원무과) or the National Health Insurance Service (국민건강보험공단).
If you do start dialysis, the hospital will explain it to you.

Disability registration

If you have had dialysis for a set period or longer, or have had a kidney transplant,
you can register as having a kidney disability.
Once registered, you become eligible for several support programs.

Ask about the criteria and the process at your community service center (주민센터) or the hospital's social work team.

Other things

• There are medical cost support programs based on income levels
• Dialysis goes on for a long time, so choosing a dialysis unit close to your home or workplace matters a lot in practice
• If the hospital has a social work team, be sure to get counselling. They help you look for programs

Please get nutrition counselling

Chronic kidney disease is a condition where what you eat is itself the treatment.
How much salt, protein, potassium and phosphorus you should have differs at each stage.

Do not decide on your own from information on the internet;
get nutrition counselling at a hospital or a public health center. It is sometimes covered by insurance.

Programmes and out-of-pocket cost rates change.
The content below is a summary as of the reference date, and you should always
check the latest criteria at the National Health Insurance Service.