Acute nephritis may present with some clinical symptoms. The main characteristics are that patients may have hematuria and proteinuria. When there is a significant amount of blood in the urine, it can be detected by the naked eye, known as gross hematuria. For instance, the color of the patient's urine could be dark like strong tea or bright red. Patients might also experience increased urine foam due to the presence of proteins in the urine, especially in cases where there is a significant presence of urinary proteins. A minority of patients may experience acute renal failure, often characterized by reduced urine output, or even anuria. Due to the reduced urine output, the water intake of patients cannot be fully excreted, leading to edema. Patients may experience swelling of the facial and bilateral lower limbs or even the whole body.