Chronic kidney disease (CKD) is when kidneys are damaged and not able to carry out their filtering and detoxifying function, leading to the build up of waste products in the blood. The condition generally gets worse over time, but progression can be stalled and markers of the disease can be reversed in some instances. CKD affects 11–13% of the global population, and 14.0% of the United States population.
CKD does not usually present overt symptoms until kidney function is impaired by 50% or more. Symptoms include fatigue, chest pain, brain fog, headaches, poor appetite, nausea, vomiting, poor sleep, nighttime muscle cramping, swelling in the feet and around the eyes, dry and itchy skin, and more frequent urination. Common signs of CKD include markers used for diagnosis— decreased GFR, increased albumin, creatinine, or cystatin — and markers of the underlying conditions — dyslipidemia, high blood pressure, glycemic dysregulation, and elevated uric acid levels.
In its early stages, CKD is often a silent disease - there are usually no symptoms to warn that something may be going awry with the kidneys. Some experts recommend that people with risk factors for CKD (e.g. those with diabetes, hypertension, heart disease) receive yearly kidney function screenings.
CKD is diagnosed when kidney function tests show markers of serious kidney damage, for example a decreased glomerular filtration rate (GFR), elevated urine albumin, and electrolyte abnormalities. Markers of kidney damage must be maintained over 3 or more months. CKD is classified based on GFR into 1 of 5 stages, where stage 1 is the least progressed disease state, and stage 5 represents kidney failure.  End-stage renal disease (ESRD) is defined as CKD stage 5 treated with dialysis.
CKD treatment includes medications to manage impaired kidney function and to address the underlying cause of further kidney damage. For the majority of people with CKD, that means getting heart disease, hypertension, and diabetes under control with medications, diet, and lifestyle changes. Treatment for CKD includes medications that lower blood pressure and block the renin-angiotensin-aldosterone system (RAAS). Other medications are used to manage uric acid levels, sodium levels, metabolic acidosis, blood lipids, blood sugar, and bone mineralization, and dialysis is used to externally purify the blood when the kidneys no longer function.
CKD compromises the kidneys’ ability to balance electrolytes and nutrients in the blood, so managing CKD involves limiting foods higher in sodium, phosphorus, and protein, and emphasizing foods high in potassium, calcium, vitamin D, and total calories. Potassium is typically restricted in later stages due to kidney damage and the use of medications that affect potassium levels.
Studies on the effects of specific diets are sparse and short-term, but show benefits to some markers of the disease. Studied diets include low- and very-low- protein diets, low salt, low fat, low carbohydrate, high fruit and vegetable, plant-based, vegan, vegetarian, Dietary Approaches to Stop Hypertension (DASH diet), Mediterranean diet, American Heart Association diet, and American Diabetes Association diet.
The most common supplements studied for CKD are amino acid supplements used in conjunction with very-low-protein diets. Others include alkalizing therapy with potassium citrate salts, vitamin D supplementation, and omega-3 fatty acid supplements. Many other supplements have been investigated, including vitamin E, antioxidant therapy, coenzyme Q10, acetylcysteine, bardoxolone methyl, and human recombinant superoxide dismutase, potassium, calcium fortification, nitrate, turmeric and boswellia, curcumin, vitamin K, B vitamins, astragalus, cordyceps, and Rheum officinale.
No alternative modalities have been well-studied for their use in managing CKD outcomes or symptoms. However, complementary modalities that promote general well-being by increasing physical activity and promoting stress reduction (acupuncture, mindfulness, tai chi, etc.) can be used to enhance well-being in those with CKD. A foundation of CKD treatment is managing conditions that cause CKD. Therefore, complementary approaches that benefit type 2 diabetes, hypertension, or heart disease may in turn benefit persons with CKD. Additionally, some modalities may help with feelings of depression and anxiety in people with CKD.
Diabetes, heart disease, and hypertension are the three most common causes of CKD. When these conditions are uncontrolled for a long period of time, they can cause severe kidney damage and impaired function, leading to a diagnosis of CKD. Other causes of kidney damage that can lead to and/or worsen CKD include systemic infections, autoimmune conditions, and chronic use of kidney-damaging drugs like chemotherapies and non-steroidal anti-inflammatories.