Final answer:
Kidney disease is a common cause of hematuria, which is the presence of blood in the urine, but intense exercise can also lead to this condition. It's one of the symptoms that can arise from various issues affecting the kidneys, including kidney stones and infections. Hematuria requires medical evaluation to establish its cause and to treat any underlying conditions.
Step-by-step explanation:
Although kidney disease is the most common reason for hematuria (blood in the urine), strenuous exercise can cause it too. Hematuria refers to the presence of red blood cells in the urine, which can result from infection, injury, or underlying medical conditions such as cystine stones, diabetes mellitus, or glomerulonephritis.
It's also a symptom of more severe conditions like diabetic nephropathy and polycystic kidney disease (PKD), both of which can lead to kidney failure. In cases of kidney failure, hematuria may accompany other symptoms like nausea, muscle cramps, and swelling of extremities.