Renal insufficiency

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at December 16, 2016
StartDiseasesRenal insufficiency

Renal insufficiency, or kidney failure, is the loss of kidney function. The condition can cause a variety of other health complications, so diagnosis and treatment is important. Fortunately, the symptoms of renal insufficiency can be controlled if there is an early diagnosis.


Definition & Facts

The kidneys are responsible for removing waste and fluids from the blood. When the kidneys are damaged or cannot function, waste builds up in the blood. Acute renal failure, or acute kidney injury, occurs when the kidneys quickly worsen in a short time. This can be halted if the patient notices and seeks treatment in time.

Chronic kidney disease develops slowly over a longer time period and usually cannot be reversed. Individuals with chronic kidney disease often do not realize they have the disease until the kidneys have been suffering for a long time.

Symptoms & Complaints

In the early stages of renal insufficiency, the individual may not notice any symptoms, or they may only notice minor symptoms. As kidney function declines, it leads to azotemia, or the buildup of waste in the blood. Minor azotemia doesn't have many noticeable symptoms, but the symptoms worsen over time.

Different types of waste buildup in the blood cause different symptoms. If an individual has high levels of urea in their blood, they will likely experience vomiting, nausea, weight loss, and either more frequent urination or less frequent urination.

If renal insufficiency is caused by high levels of phosphates, the individual may suffer from bone damage, muscle cramps, or severe itching. High potassium levels can cause muscle paralysis and abnormal heart rhythms. Failing kidneys often produce less erythropoietin than usual, which results in a decrease in red blood cells. This can lead to anemia, which causes dizziness, fatigue, and low blood pressure.

Other general symptoms of renal insufficiency include headaches, loss of appetite, and a metallic taste in the mouth. Some severe symptoms include darkening or lightening of the skin, numbness in the hands or feet, and shortness of breath.


Acute kidney injury typically occurs when there is a sudden interruption in blood flow to the kidneys. This can be caused by injuries, accidents, complications from surgery, or drug overdoses. The cause of chronic renal insufficiency is not always as obvious, but the most common causes are diabetes and high blood pressure. The high blood sugar levels caused by diabetes can result in damaged blood vessels in the kidneys, which affects kidney functioning.

High blood pressure can also damage the kidney's blood vessels. In some cases, renal insufficiency is caused by a blockage or narrowing in the renal artery, the artery that carries blood to the kidneys. Frequent or prolonged use of medicines that affect the kidneys, like ibuprofen and some antibiotics, can cause renal insufficiency. Birth defects in the kidneys also can cause kidney failure. For example, polycystic kidney disease, a genetic disorder that causes cysts to form in the kidneys, sometimes impairs kidney functioning.

Diagnosis & Tests

Tests for renal insufficiency can diagnose the condition and determine how long the kidneys have been troubled, what caused the damage, and what treatment will be the most effective. Most tests measure the levels of different substances that build up in the blood when an individual has kidney damage. A creatinine test measures the amount of creatine in the blood to estimate the glomerular filtration rate, or GFR. GFR can tell the doctors what stage of damage the kidneys are at and can provide more information about how well the kidneys are working.

A blood urea nitrogen test measures how much nitrogen is in the blood from urea buildup. Urea is one of the most common substances to accumulate in the blood with renal insufficiency, so the blood urea nitrogen test is popular for diagnosing the condition. Patients with renal insufficiency may also have a renal ultrasound, which can estimate how long the kidneys have been declining.

Individuals with diabetes may take a fasting blood glucose test to determine whether high blood sugar levels could be causing kidney damage. Doctors recommend that people with diabetes and high blood pressure have occasional screening tests for renal insufficiency because early detection is very helpful for treating the condition.

Treatment & Therapy

If renal insufficiency is caused by another disease, treating the original disease is usually the priority. When kidney damage is caused by high blood pressure, doctors often prescribe a blood pressure medication like an ACE inhibitor. Lowering blood pressure can prevent the kidney damage from worsening. If diabetes is responsible for renal insufficiency, controlling blood sugar levels can help treat the damage.

Healthy lifestyle choices can often help treat the condition, regardless of the cause of the damage. Doctors usually recommend that patients limit their intake of salt, protein, and fluids. However, protein and fluids are still important for health, so dieticians can help patients determine a meal plan that will include a safe amount.

Individuals with renal insufficiency should usually try to eat four or five small meals throughout the day rather than two or three larger meals. Avoiding substances like alcohol and tobacco can also help kidney functioning return to normal. Patients should also see a doctor periodically to make sure the kidney damage hasn't worsened or resulted in complications.

Prevention & Prophylaxis

It can be challenging to prevent chronic kidney disease because the symptoms often don't appear until the kidneys have been affected for a long period of time. However, people at a high risk for the disease, like people with high blood pressure or diabetes, can prevent renal insufficiency by controlling those conditions and visiting the doctor frequently for tests.

When a patient discovers kidney damage early on, treating the damage is very feasible. Patients who already have kidney disease can prevent their kidneys from worsening with medication and diet and lifestyle changes. Maintaining a healthy weight, controlling cholesterol levels, and avoiding smoking and other tobacco products can prevent further damage to the kidneys. With treatment and preventive measures, kidney damage can often be reversed over time.