What are the symptoms of decreased renal concentrating ability?

Declined renal concentrating ability is one manifestation of declined renal function. The main symptoms include polyuria, increased nocturia, lighter urine color, and electrolyte imbalance.

1. Polyuria and increased nocturia: Normally, the urine volume of an adult is approximately 1000~2000ml within 24 hours. When renal function is abnormal, renal tubules are damaged. At this point, urine concentration and reabsorption functions are impaired, leading to increased urine volume. The reabsorption capacity of renal tubules further decreases at night, resulting in increased nocturia.

2. Lighter urine color: This is mainly related to the decreased specific gravity of urine, which is one of the most important indicators for detecting renal concentrating ability. When renal concentrating ability declines, the specific gravity of urine also decreases because the kidneys can only produce lighter urine at this time.

3. Electrolyte imbalance: Electrolytes in blood and urine can also reflect renal concentrating ability. When renal concentrating ability declines, the excretion of substances such as water, potassium, sodium, and calcium increases, easily leading to electrolyte imbalance. Hypokalemia manifests as weakness in the limbs. When hypocalcemia occurs, symptoms such as limb convulsions may appear. Electrolyte imbalance can also manifest as digestive system symptoms such as nausea, vomiting, and appetite loss. More severe patients may also exhibit symptoms related to heart failure, such as dyspnea and shortness of breath. Some patients also experience discomfort in the kidneys, such as lumbar pain, or facial edema and lower limb edema. When renal concentrating ability is found to be declined, one should promptly undergo relevant examinations at a formal hospital to avoid delaying the condition.