Renal Disorder

Renal disorders affect millions of people worldwide, often developing silently over time, but with proper care and early detection, many individuals can manage these conditions and maintain a good quality of life.

Table of contents

• What is renal disorder?
• Understanding how your kidneys work
• Types of kidney disease
• Signs and symptoms
• Causes and risk factors
• Stages of chronic kidney disease
• Diagnosis and testing
• Treatment options
• Living with kidney disease
• Prevention

What is renal disorder?

Renal disorder, also called kidney disease, means your kidneys are damaged and can’t filter blood the way they should^[1]. Your kidneys filter extra water and wastes out of your blood and make urine^[2]. When kidney disease occurs, the kidneys cannot filter blood as well as they should, which can lead to other health problems, such as heart disease and stroke^[6].

There are two main types of renal disorders. Acute kidney failure (also called acute kidney injury) is loss of kidney function that develops quickly — over a few hours or days. Many people with acute kidney injury will recover over time, which could take days, weeks or months^[8]. Chronic kidney disease is when your kidneys have been damaged in a way that can’t be reversed. Chronic kidney disease takes months or years to develop^[8].

Understanding how your kidneys work

You have two kidneys, each about the size of your fist. They are bean-shaped organs located near the middle of your back, just below the rib cage^[3]. Most people have two working kidneys, but you can live well with only one kidney as long as it’s functioning well^[5].

Inside each kidney there are about a million tiny structures called nephrons. They filter your blood, removing wastes and extra water, which become urine^[3]. Your kidneys filter all the blood in your body every 30 minutes^[6].

Your kidneys have many important jobs beyond cleaning your blood. They help control blood pressure, signal the body to make red blood cells, help keep your bones healthy, and regulate blood chemicals that are essential to life^[6]. They also turn vitamin D into its active form, so it’s usable in the body^[1].

Types of kidney disease

Most kidney diseases attack the nephrons. This damage may leave kidneys unable to remove wastes^[3]. There are many different types of kidney conditions, each with its own causes and characteristics.

Chronic kidney disease is a condition in which the kidneys are damaged and can’t filter blood as well as they should^[6]. It is characterized by progressive damage and loss of function in the kidneys, and it’s estimated that chronic kidney disease affects about one in seven American adults^[1]. More than 1 in 7 American adults has chronic kidney disease, and as many as 9 in 10 don’t know they have it^[6].

Other kidney problems include cancer, cysts, stones, and infections^[3]. Specific conditions mentioned in medical sources include IgA nephropathy, polycystic kidney disease, lupus nephritis, glomerular disease, and amyloidosis^[2].

Signs and symptoms

Many people experience few or no symptoms in the early stages of kidney disease. However, chronic kidney disease may still cause damage even though you feel fine^[5]. People with kidney disease may not feel ill or notice any symptoms, which is why the only way to find out for sure if you have kidney disease is through blood and urine tests^[6].

If your kidneys aren’t working properly, you may notice one or more of the following signs^[5]:

• Extreme tiredness (fatigue)
• Nausea and vomiting
• Confusion or trouble concentrating
• Swelling (edema), particularly around your hands, ankles or face
• A change in how often you pee
• Cramps (muscle spasms)
• Dry or itchy skin
• Poor appetite, or food may taste metallic

In acute kidney failure, the first symptom is often a decreased amount of urine^[8]. If you notice you are suddenly making less urine than usual together with other symptoms of acute kidney failure, see your doctor urgently or go to your local hospital emergency department^[8].

Causes and risk factors

Diabetes and high blood pressure are the most common causes of chronic kidney disease and kidney failure^[5]. Unmanaged diabetes can lead to high blood sugar levels that damage the kidneys over time. Approximately 1 in 3 adults with diabetes, and 1 in 5 adults with high blood pressure, may have chronic kidney disease^[23].

There are quite a few things that can cause or put you at higher risk for chronic kidney disease. Some of them are not things that can be avoided. Your risk is simply higher if you have a family history of certain genetic conditions like polycystic kidney disease or some autoimmune diseases like lupus or IgA nephropathy^[1].

You are at greater risk for kidney disease if you have^[2]:

• Diabetes
• High blood pressure
• Heart disease
• A family history of kidney failure

Your risk also increases as you get older^[1]. Other factors that can increase risk include obesity and certain racial or ethnic backgrounds^[9].

Stages of chronic kidney disease

There are five stages of chronic kidney disease. The stages are based on how well your kidneys are able to filter out waste from your blood^[17]. Blood and urine tests determine which stage you’re in^[5].

Healthcare providers determine the stage of your kidney function according to the glomerular filtration rate (GFR). Your GFR is a number based on the amount of creatinine, a waste product, found in your blood. Your eGFR is a calculation of how well your kidneys filter substances. A normal eGFR is above 90. The lowest eGFR is 0, which means there’s no remaining kidney function^[5].

The five stages include^[5]:

• Stage 1: Your GFR is higher than 90. At this stage, your kidneys have mild damage but still function normally.
• Stage 2: Your GFR may be as low as 60 or as high as 89. You have more damage to your kidneys than in stage 1, but they still function well.
• Stage 3: Your GFR may be as low as 30 or as high as 59. You may have mild or severe loss of kidney function. You may notice symptoms at this stage.
• Stage 4: Your GFR may be as low as 15 or as high as 29. You have severe loss of kidney function.
• Stage 5: Your GFR is below 15. Your kidneys are nearing or at complete failure. Generally, this is when you would start to have symptoms.

Kidney failure can worsen to the most severe stage, end-stage kidney disease (ESKD) which is deadly without treatment^[5]. Not all people with kidney disease progress to kidney failure^[6].

Diagnosis and testing

Early kidney disease may not have any symptoms, so getting tested may be the only way to know your kidneys are healthy^[22]. Specific blood and urine tests are needed to check for chronic kidney disease^[6]. Your doctor can do blood and urine tests to check if you have kidney disease^[3].

These tests measure both the creatinine level in the blood and protein in the urine^[6]. Blood tests can check your estimated glomerular filtration rate (eGFR), which shows how well your kidneys are filtering^[2]. Urine tests can detect protein in the urine, which is a sign of kidney damage^[2].

During your next medical visit, you may want to ask your healthcare provider about your kidney health. Your healthcare provider will help decide how often you should be tested^[22].

Treatment options

There’s no cure for chronic kidney disease, but treatment can help relieve the symptoms and stop it getting worse^[11]. Your treatment will depend on the stage of your chronic kidney disease^[11]. While it’s not possible to reverse kidney damage, you can take steps to slow it down^[23].

The main treatments are^[11]:

• Lifestyle changes – to help you stay as healthy as possible
• Medicine – to control associated problems, such as high blood pressure and high cholesterol
• Dialysis – treatment to replicate some of the kidney’s functions, which may be necessary in advanced (stage 5) chronic kidney disease
• Kidney transplant – this may also be necessary in advanced (stage 5) chronic kidney disease

There’s no medicine specifically for chronic kidney disease, but medicine can help control many of the problems that cause the condition and the complications that can happen as a result of it^[11]. You may need to take medicine to treat or prevent different problems caused by chronic kidney disease, such as high blood pressure, diabetes, high cholesterol, and high potassium levels^[11].

If your kidneys fail, you will need dialysis or a kidney transplant^[3]. Dialysis is a treatment that performs some of the functions your kidneys would normally do. There are two different types: hemodialysis, which is done through cleaning the blood through a machine, and peritoneal dialysis, where fluid gets put into your tummy, takes out the toxins and is drained^[10].

A kidney transplant involves surgically placing a healthy kidney from a donor into your body. This may be necessary in advanced stage 5 chronic kidney disease^[2]. With the proper treatment, you can have a good quality of life while you manage kidney failure^[5].

Living with kidney disease

Many people with chronic kidney disease are able to live long lives without being unduly affected by the condition^[24]. Taking an active role in managing chronic kidney disease will help you feel better and improve your overall well-being^[23].

Important steps for living well with kidney disease include^[11]:

• Stop smoking if you smoke
• Eat a healthy, balanced diet that includes plenty of fruit and vegetables, meals with starchy foods, and low levels of saturated fat, salt and sugar
• Restrict your salt intake to less than 6g a day – that’s around 1 teaspoon
• Do regular exercise – aim to do at least 150 minutes a week
• Manage your alcohol intake so you drink no more than the recommended limit
• Lose weight if you’re overweight or obese
• Avoid over-the-counter anti-inflammatory drugs unless advised by a medical professional

Physical activity is good for anyone with kidney disease, whether you have mild, moderate, or severe chronic kidney disease. It can boost your energy, help you sleep, strengthen your bones, and help prevent depression^[23].

If you have diabetes and chronic kidney disease, finding the best foods to eat can be challenging. Some foods that work for both diabetes and chronic kidney disease include fruits like berries, grapes, cherries, apples, and plums; vegetables like cauliflower, onions, and eggplant; lean meats, fish, and eggs; and drinks like water, clear diet sodas, and unsweetened tea^[23].

It’s very important that you take any prescribed medicine, even if you do not feel unwell. Some medicines are designed to prevent serious problems from happening in the future^[24]. Check with a doctor or pharmacist if you plan to take any over-the-counter medicines such as painkillers or nutritional supplements, as these can sometimes affect your kidneys or interfere with your prescribed medicine^[24].

Prevention

You can protect your kidneys by preventing or managing health conditions that cause kidney damage, such as diabetes and high blood pressure^[22]. The steps to prevent kidney disease may help keep your whole body healthy, including your kidneys^[22].

To reduce your risk of kidney disease^[6]:

• Keep your blood pressure below 140/90 mm Hg (or the target your doctor sets for you)
• If you have diabetes, stay in your target blood sugar range as much as possible
• Get active. Physical activity helps control blood pressure and blood sugar levels
• Lose weight if needed
• Get tested for chronic kidney disease regularly if you’re at risk
• If you have chronic kidney disease, meet with a dietician to create a kidney-healthy eating plan
• Take medicines as instructed
• If you smoke, make a plan to quit

Choose foods that are healthy for your heart and your entire body: fresh fruits, fresh or frozen vegetables, whole grains, and low-fat or fat-free dairy products. Eat healthy meals, and cut back on salt and added sugars. Aim for less than 2,300 milligrams of sodium each day^[22].

Getting your annual flu shot and keeping up with other recommended vaccinations is also important for protecting your health when you have kidney disease^[23].