What is renal tubular acidosis?
Renal tubular acidosis (RTA) occurs when the kidneys do not remove acids from the blood into the urine as they should. The acid level in the blood then becomes too high, a condition called acidosis. Some acid in the blood is normal, but too much acid can disturb many bodily functions.
How common is RTA?
RTA is a rare disease that is often misdiagnosed or undiagnosed,1 making it difficult to determine the true frequency in the general population.2
What are the complications of RTA?
Type 1 RTA
Untreated type 1 RTA causes children to grow more slowly and adults to develop progressive kidney disease and bone diseases NIH external link. Adults and children with untreated type 1 RTA may develop kidney stones because of abnormal calcium deposits that build up in the kidneys. These deposits prevent the kidneys from working properly.
Type 2 RTA
Untreated type 2 RTA may cause children to grow more slowly. In addition, type 2 RTA may cause rickets NIH external link5—a bone disease—and dental disease in both children and adults.6 A very low potassium level can develop during treatment of type 2 RTA with alkali.4
Type 4 RTA
In people with type 4 RTA, high levels of potassium in the blood can lead to muscle weakness7 or heart problems, such as slow or irregular heartbeats NIH external link and cardiac arrest NIH external link.
What are the signs and symptoms of RTA?
The major signs of type 1 RTA and type 2 RTA are low levels of potassium and bicarbonate—a waste product produced by your body—in the blood. The potassium level drops if your kidneys send too much potassium into your urine instead of returning it to the blood.
What are the causes of RTA?
Type 1 RTA
Type 1 RTA may be inherited. Researchers have identified at least three different genes that may cause the inherited form of the disease.2 People with sickle cell anemia NIH external link or Ehlers-Danlos syndrome, which are also inherited, may develop type 1 RTA later in life.
However, type 1 RTA may develop because of an autoimmune disease, such as Sjögren’s syndrome or lupus, that can affect many parts of the body. These diseases may interfere with the removal of acid from your blood.
Type 4 RTA
Type 4 RTA can occur when blood levels of the hormone aldosterone are low or when the kidneys do not respond to the hormone. Aldosterone directs the kidneys to regulate the level of sodium, which also affects the levels of chloride and potassium, in the blood.
How do health care professionals diagnose RTA?
Your health care professional will review your medical history and order blood NIH external link and urine tests NIH external link to measure the levels of acid, base, and potassium in your blood and urine. If your blood is more acidic than it should be and your urine is less acidic than it should be, RTA may be the reason, but a health care professional will need to rule out other causes.
How do health care professionals treat RTA?
For all types of RTA, drinking a solution of sodium bicarbonate NIH external link or sodium citrate will lower the acid level in your blood. This alkali therapy can prevent kidney stones from forming and make your kidneys work more normally so kidney failure does not get worse.
Infants with type 1 RTA may need potassium supplements, but older children and adults rarely do because alkali therapy prevents the kidneys from excreting potassium into the urine.
How can I prevent RTA?
Inherited types of RTA cannot be prevented,10 and most of the disorders that cause RTA are not preventable.
How does eating, diet, and nutrition affect RTA?
Researchers don’t yet know whether a diet low in acidic foods can have a positive effect on RTA.
Clinical Trials for Renal Tubular Acidosis
The NIDDK conducts and supports clinical trials in many diseases and conditions, including kidney diseases. The trials look to find new ways to prevent, detect, or treat disease and improve quality of life.
What clinical studies for RTA are looking for participants?
You can find clinical studies on RTA at www.ClinicalTrials.gov NIH external link. In addition to searching for federally funded studies, you can expand or narrow your search to include clinical studies from industry, universities, and individuals; however, the National Institutes of Health does not review these studies and cannot ensure they are safe. Always talk with your health care provider before you participate in a clinical study.