Renal tubular acidosis (RTA) is a condition that interferes with normal kidney function. It has a wide range of symptoms, including bone problems, reduced growth, and an abnormal heart rate.

Symptoms can vary depending on the type of RTA a person has.

Doctors can detect RTA with urine tests. The outlook for people with this condition varies according to the underlying cause.

This article provides an overview of RTA. It then lists the more common symptoms. The article will also discuss the diagnosis, complications, and outlook for RTA.

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RTA is a condition that affects the kidneys.

Usually, the kidneys filter waste products from the blood before releasing them into the urine. In people with RTA, the kidneys do not remove enough acids from the blood. As a result, the blood becomes too acidic. Doctors call this acidosis.

The kidneys are complex organs. They contain many tubules, which are tiny tube-like structures. These tubules help with expelling waste products. RTA disrupts kidney function by causing problems with the tubules.

There are four main types of RTA. Each type has a distinctive effect on kidney tubules:

  • Type 1 RTA: Also known as distal RTA. It is a problem with the end part of the tubules.
  • Type 2 RTA: Doctors sometimes call this proximal RTA. It affects the beginning part of the tubules.
  • Type 3 RTA: This is a combination of type 1 and type 2 RTA.
  • Type 4 RTA: Also known as hyperkalemic RTA. It occurs when the kidney tubules cannot remove enough potassium from the blood.

The symptoms of RTA vary from type to type.

Some RTA symptoms arise from over-acidic blood. Others occur because RTA can create an abnormal concentration of bases in the urine.

Type 1 RTA can cause the following symptoms:

  • growth failure
  • softening of the bones
  • weakening of the bones
  • bone pain
  • bone deformities
  • recurrent urinary tract infections
  • muscle weakness
  • irregular heartbeat

Type 2 RTA has symptoms in common with type 1 RTA, as well as others:

  • softening of the bones
  • weakening of the bones
  • bone pain
  • bone deformities
  • loss of glucose and amino acids

Type 3 RTA can cause the same symptoms as types 1 and 2 RTA.

Types 1, 2, and 3 RTA cause abnormally low blood potassium levels. This low blood potassium level explains certain symptoms that we list above.

Type 4 RTA causes abnormally high blood potassium levels. This can result in the following symptoms:

  • weakness
  • fatigue
  • heart palpitations
  • fainting

In many cases, elevated potassium levels do not cause obvious symptoms.

Anyone with symptoms of RTA should seek medical attention. Doctors can perform diagnostic tests for RTA.

There are several tests for RTA that all involve analyzing a urine sample. RTA tends to cause different concentrations of ions, which are detectable in a person’s urine.

There are several potential complications of RTA. The National Institutes of Health (NIH) notes that in adults and children, RTA can cause rickets. This is a condition that can lead to serious problems with the bones and may result in significant bone deformities.

RTA can also lead to serious heart problems, including cardiac arrest. Some people with RTA will also develop kidney stones.

According to a 2016 review in the Ochsner Journal, the outlook for people with RTA varies. While some people experience few symptoms and require little treatment, others will develop end-stage renal disease.

The severity of RTA depends upon its underlying cause. RTA has many possible causes.

According to the NIH, RTA can arise due to the following:

  • genetics
  • some autoimmune diseases, such as lupus or Sjogren’s syndrome
  • some medications, including painkillers and antibiotics
  • a urinary tract blockage
  • kidney disease
  • kidney transplant rejection

The kidneys help filter a person’s blood. RTA occurs when kidney tubules have trouble expelling acidic waste products. This can happen for several reasons. Kidney problems, medications, autoimmune diseases, and heredity can all cause RTA.

There are different types of RTA. Each type affects the kidney tubules in its own way.

As a result, RTA can cause many different symptoms, including bone weakness, bone pain, and bone deformities. RTA can also cause muscle weakness, heart problems, and urinary tract infections.

Doctors diagnose RTA with urine tests. A diagnosis of RTA may allow people to receive treatment for its underlying cause. This can sometimes mean a positive outlook. In other cases, RTA can progress to more serious kidney disease.