Renal Tubular Acidosis symptoms include an increased amount of acid in the blood (called acidosis). This may cause symptoms that can be difficult to control, such as nausea, vomiting, tachycardia and/or arrhythmia.
All living things need an ideal balance of acid and base (alkali) in their bodies, called pH. The kidneys help keep this balanced by filtering and removing wastes from the blood. They also regulate electrolyte balance and stimulate red blood cell production.
The kidneys do these things by sending signals to each other in tiny structures called nephrons. Each nephron has a tube, called a renal tubule, that connects to the blood. The tubules filter acid and wastes from the blood, then secrete them into urine.
A defect or damage in one of these tubes can lead to an abnormal buildup of acids and other substances in the urine, which can lead to RTA. Some defects in the tubules can be inherited and cause permanent RTA. Others are caused by certain diseases or other conditions, such as high blood calcium levels, sickle cell disease, autoimmune disorders like lupus and Sjogren syndrome, or the use of certain drugs.
Type 1: Distal renal tubular acidosis
This is the most common form of RTA and happens when there is a problem with a part of the kidney that resorbs bicarbonate. It usually happens in children and is related to a disorder called Fanconi syndrome, which occurs when certain needed minerals are passed into the urine instead of being reabsorbed into the bloodstream. Vitamin D deficiency, fructose intolerance, and other diseases can also cause this type of RTA.
Type 2: Proximal renal tubular acidosis
This type of RTA happens closer to the beginning of the kidney’s tubules, and is more common in infants as a symptom of disorders that prevent the body from breaking down and using nutrients correctly. It can occur as a symptom of cystinosis (a condition in which the amino acid cystine builds up in the body and damages cells), Wilson’s disease, or some other inherited disorders.
Symptoms of proximal RTA may include muscle weakness, polydipsia and polyuria, as well as low potassium levels in the blood. The condition can be very dangerous and may lead to a life-threatening condition called hyperkalemic RTA, which is caused by the body’s inability to transport potassium properly.
Type 3: Interstitial renal tubular acidosis
This form of RTA is more rare than the other two forms and occurs when there is a problem with the reabsorption of filtered bicarbonate in the kidney’s ducts. It usually happens in patients with underlying diseases that affect the reabsorption of sodium and potassium. It can also be a complication of certain types of surgery and drug therapy.
This form of RTA is often a complication of diabetes mellitus, and it can lead to other problems such as nephrocalcinosis, or buildup of calcium in the kidneys. It can also lead to a serious form of kidney disease called glomerulonephritis.