Can I drink water before a routine urine test?

In general, it is acceptable to drink an appropriate amount of water before a routine urine test, but attention should be paid to the timing and quantity. Moderate water intake will not significantly affect the results of a routine urine test; however, excessive water consumption can dilute the urine and may influence the accuracy of certain indicators, such as urine specific gravity, protein, and glucose levels. To obtain more accurate test results, it is recommended not to drink large amounts of water 2–4 hours before the test. If a morning urine sample is required, it is best to collect the first void upon waking, as this urine is more concentrated and better reflects the body's actual condition.

When preparing for a routine urine test, follow these guidelines: the night before the test, try to avoid consuming excessive fluids to ensure appropriate urine concentration. On the morning of the test, you may drink a small amount of water after waking, but do not overconsume. Use a clean container to collect the urine sample, typically the midstream portion—urine collected during the middle part of urination—to reduce the risk of external contamination. Deliver the urine sample for testing as soon as possible after collection to avoid bacterial growth or chemical changes due to prolonged storage. If your doctor provides specific instructions, such as requiring fasting or other special preparations, be sure to follow them strictly.