The cause of chronic kidney disease isn't always known. But any condition or disease that damages blood vessels or other structures in the kidneys can lead to kidney disease. The most common causes of chronic kidney disease are:

Diabetes . High blood sugar levels caused by diabetes damage blood vessels in the kidneys. If the blood sugar level remains high over many years, this damage gradually reduces the function of the kidneys.
High blood pressure (hypertension). Uncontrolled high blood pressure damages blood vessels, which can lead to damage in the kidneys. And blood pressure often rises with chronic kidney disease, so high blood pressure may further damage kidney function even when another medical condition initially caused the disease.

When you have kidney disease, your kidneys are no longer working as well as they need to. Changing your diet can help protect your kidneys. It can also help you control other diseases, such as diabetes and high blood pressure, that can make kidney disease worse.

This topic can give you some general ideas about how to follow the diet your doctor or dietitian recommends.

You might not notice any problems if you have chronic kidney disease that’s in the early stages. Most people don’t have symptoms at that point. That’s dangerous, because the damage can happen without you realizing it.

If your chronic kidney disease is already more advanced, you may:

Be vomiting or often feel like you’re going to
Pee more often than normal, or less often
See “foam” in your pee
Have swelling, particularly of the ankles, and puffiness around the eyes
Feel tired or short of breath all the time
Not feel like eating
Not be able to taste much
Have muscle cramps, especially in your legs
Have very dry, itchy skin
Sleep poorly
Lose weight for no obvious reason

These diet tips are not for you if you are on dialysis or have had a kidney transplant. Follow the special diet your doctor gave you.

Most people who have kidney disease need to limit salt (sodium), fluids, and protein. Some also have to limit potassium and phosphorus.
There is no one diet that is right for everyone who has kidney disease. Your doctor or dietitian can tailor a diet for you based on how well your kidneys are working.
It may be hard to change your diet. You may have to give up many foods you like. But it is very important to make the recommended changes so you can stay healthy for as long as possible.
You need to get enough calories to be healthy and have energy. If you have a hard time eating enough, talk to your doctor or dietitian about ways to add calories to your diet.
Your diet may change over time as your disease changes. See your doctor for regular testing, and work with a dietitian to adjust your diet as needed.

Don't skip meals or go for many hours without eating. If you don't feel very hungry, try to eat 4 or 5 small meals instead of 1 or 2 big meals.
If you have trouble keeping your weight up, talk to your doctor or dietitian about ways you can add calories to your diet. Healthy fats such as olive or canola oil may be good choices. Unless you have diabetes, you can use honey and sugar to add calories and increase energy.
Don't take any vitamins or minerals, supplements, or herbal products without talking to your doctor first.
Check with your doctor about whether it is safe for you to drink alcohol. If you do drink alcohol, have no more than 1 drink a day. Count it as part of your fluids for the day.

AnemiaAnemia. You may feel weak, have pale skin, and feel tired, because the kidneys can't produce enough of the hormone (erythropoietin) needed to make new red blood cells.
Electrolyte imbalanceElectrolyte imbalance. When the kidneys can't filter out certain chemicals, such as potassium, phosphate, and acids, you may have an irregular heartbeat, muscle weakness, and other problems.
Uremic syndromeUremic syndrome. You may be tired, have nausea and vomiting, not have an appetite, or not be able to sleep when substances build up in your blood. The substances can be poisonous (toxic) if they reach high levels. This syndrome can affect many parts of your body, including the intestines, nerves, and heart.
Heart disease . Chronic kidney disease speeds up hardening of the arteries (atherosclerosis) and increases the risk of stroke, heart attack, and heart failure. Heart disease is the most common cause of death in people with kidney failure.
Bone disease (osteodystrophy). Abnormal levels of substances, such as calcium, phosphate, and vitamin D, can lead to bone disease.
Fluid buildup (edema). As kidney function gets worse, fluids and salt build up in the body. Fluid buildup can lead to heart failure and pulmonary edema.