munuaistaiehyistä

Munuaistaiehyistä, also known as renal tubular acidosis (RTA), refers to a group of disorders affecting the kidneys' ability to properly excrete acids and reabsorb bicarbonate. This leads to an imbalance in the body's acid-base levels, specifically a metabolic acidosis. There are several types of RTA, each with distinct causes and mechanisms.

Type 1 RTA, or distal RTA, occurs when the distal tubules are unable to secrete sufficient hydrogen ions into the urine. This can be caused by genetic factors, autoimmune diseases, or certain medications. Patients with type 1 RTA often have difficulties concentrating their urine, leading to increased thirst and urination.

Type 2 RTA, or proximal RTA, is characterized by a defect in the proximal tubules' ability to reabsorb bicarbonate from the filtrate. This results in excessive loss of bicarbonate in the urine. Causes include genetic disorders, heavy metal poisoning, and certain medications. Type 2 RTA can sometimes lead to skeletal abnormalities due to impaired phosphate reabsorption.

Type 4 RTA, or hyperkalemic RTA, is the most common form and is usually associated with aldosterone deficiency or resistance. Aldosterone is a hormone that promotes sodium reabsorption and potassium excretion in the kidneys. When aldosterone function is impaired, potassium levels in the blood rise (hyperkalemia), and acid excretion is reduced. This type is often seen in individuals with diabetes or kidney disease.

Regardless of the type, untreated RTA can lead to a range of symptoms including fatigue, muscle weakness, kidney stones, and growth retardation in children. Diagnosis typically involves blood and urine tests to assess electrolyte levels, acid-base balance, and kidney function. Treatment strategies focus on correcting the acidosis with alkali supplements and managing any underlying causes.