It may come as a surprise that chronic kidney disease (CKD) can be active in the body for years before many of its symptoms become readily observable. Unlike acute kidney failure, which can result suddenly from a severe injury, kidney failure from CKD is a gradual process.
Through the first three of the five kidney disease stages, symptoms are usually so subtle that blood tests, urine tests, and/or CT scans are necessary for a diagnosis. In stages 1 and 2, evidence of the disease is most often limited to the presence of proteins in the urine, and elevated amounts of creatinine (a metabolic waste from muscle use) in the bloodstream.
It’s often not until the disease has reached its advanced stages that most symptoms manifest. Once they do, they usually can’t be ignored, and shouldn’t be. Keep in mind that, experienced in isolation, several of the following symptoms may have causes other than kidney disease. In the late stages of CKD, however, many symptoms may appear at the same time and will have direct connections to the significant loss of kidney function.
Here are some of the most common symptoms of chronic kidney disease that you may experience.
Causes and Comorbidities of CKD
There are several health conditions associated with chronic kidney disease that are unusual in that they cause, or contribute to, the development of CKD and also be caused by that disease.
- Diabetes. When kidneys fail to filter out urea, its buildup in the blood impairs insulin secretion, leading to the development of diabetes. Diabetes is the leading cause of CKD.
- Hypertension. Like diabetes, hypertension (high blood pressure) is a primary cause of CKD as well as a common symptom of it.
- Heart disease. Heart disease supplies the kidneys with an insufficient amount of blood. Kidney disease places strain on the heart by not regulating the hormones that regulate blood pressure. Heart disease is the third leading cause of CKD and the leading cause of death for people with CKD.
- Anemia. Anemia is an insufficient number of healthy, oxygen-carrying red blood cells in the bloodstream. This can result in fatigue and a feeling of being cold all the time. While it hasn’t been proven to be a primary cause of CKD, anemia is a common comorbidity and complicating factor of kidney disease, particularly in the later stages.
Changes in urine and urination due to CKD
It’s to be expected that damage to the kidneys, which filter wastes and excess fluid from the bloodstream and send them to the bladder in the form of urine, will result in changes to urine and the process of excreting it. These symptoms include:
- Blood in urine. Diabetes and hypertension, common causes of CKD in older adults, damage the small blood vessels of the kidneys, allowing blood to leak into the urine.
- Dark urine. This is a brown or reddish-purple color. Healthy urine is pale yellow in color.
- Reduced urine output. As kidneys weaken, they slow their production of urine.
- More frequent urination, particularly at night. While your actual urine output may be reduced, the urge to urinate may become more frequent.
- Sensation of internal pressure while urinating. The physical urge to urinate coupled with the inability to do so can create this sensation of pressure or strain.
- Foamy urine. Proteins, especially albumin, in the urine reduce its surface tension, causing the urine to bubble. Healthy kidneys prevent proteins from leaking into urine.
Pain, spasms, and other sensations
Far from only affecting excretion, failing kidney function affects every system, organ, and gland of the body. Some of the more noticeable symptoms include:
- Pain in the side, or in mid to lower back. In the case of only one kidney failing, the pain will occur on the side of the bad kidney. CKD can also cause kidney stones and fluid-filled cysts to develop, which can worsen the pain in those areas.
- Muscle cramps and/or twitches. As with athletes, these symptoms are thought to be caused by fluid and electrolyte imbalances, though they also may result from nerve damage and/or blood flow issues.
- Persistently itchy skin. Also called pruritus, or uremic pruritus, this may be felt all over the body, and is due to the buildup of wastes, especially excess phosphorus, that the kidneys are no longer filtering out. Pruritus is common to end-stage kidney disease.
- Feeling cold all the time. This is a symptom of anemia (see Causes and co-morbidities, above).
Appetite and weight changes
The collective effects of the physical and emotional strain of the disease, its related complications, and its treatments, can wreak havoc on your appetite, which can cause weight changes and further health issues.
- Nausea and vomiting. For those with CKD, nausea and vomiting may include uremic toxin buildup, medications, gastroparesis (when your stomach empties too slowly), peptic ulcers (people with CKD are at higher risk than those without), gastroesophageal reflux disease (GERD), and gallbladder disease, among others.
- Loss of appetite. In the early to middle stages of kidney disease, compounds build in the blood that suppress appetite and can affect your sense of taste. Foods you once enjoyed may start to taste metallic. Depression, anxiety, or medications and other treatments can contribute to appetite loss.
- Weight loss. Weight loss is most common during the early and middle stages of the disease, as one’s eGFR is dropping from the normal range, as a result of loss of appetite. Many people start to avoid meat and other proteins in particular. This can lead to malnutrition, wasting, confusion, and fatigue. Both fat and muscle consumption by the body contribute to the overall weight loss.
- Weight gain. As failing kidneys stop filtering out excess fluid, the fluid remains trapped in the body’s tissues, causing water weight gain. This is not excess fat. Due to appetite loss, many people in advanced stages of kidney disease take in few calories, so are actually malnourished.
- Swelling or puffiness, especially in the face, hands, feet, and ankles. Swelling, or edema, results from the buildup of excess fluids that the kidneys are no longer removing. Swelling in the face, hands, feet, and ankles is one of the most noticeable outward signs of renal failure.
Other symptoms of CKD
There are a variety of other symptoms that you might not automatically associate with kidney disease, but which are nonetheless commonly experienced by those living with CKD.
- Shortness of breath. This results from anemia depriving the body of oxygen, and/or pressure caused by the buildup of fluid in the body, particularly in the lungs.
- Fatigue. Fatigue occurs as the body becomes exhausted from fighting the systemic toxicity. It is also frequently caused, and exacerbated by, anemia.
- Insomnia. Despite fatigue, many patients with CKD experience insomnia. This phenomenon can have a number of causes, including medication side effects, worried thoughts, physical discomfort, and impacts from concurrent illnesses or conditions.
- Mental fuzziness. Cognitive sluggishness can result from medication side effects, drug interactions, dehydration, blood toxicity, malnutrition, hormonal imbalances, high or low blood pressure, and a variety of other sources. It can be exacerbated by fatigue and lack of sleep.
- Erectile dysfunction (ED). Sexual desire is largely controlled by the body’s endocrine (hormonal) system, and the kidneys support that system. Hypertension and diabetes alone (common causes of CKD) can cause ED, but damaged kidneys also cause poor circulation, hormonal imbalances, impaired nerve function, and reduced energy levels.
- Breath carries traces of an ammonia-like smell. Also called “uremic fetor,” this occurs when the excess urea that builds up in your body reacts with your saliva, forming ammonia.
- Brittle bones. Too much phosphorus in the blood leeches calcium from the bones, causing them to become porous and weak.
The above list is not exhaustive by any means, but describes some of the most common symptoms that you can expect, and prepare for, should the disease progress to later stages. If you notice any of the above symptoms, consult with your doctor to explore symptom management options.