At-Home Lab Test: What It Is, Why You May Need It, and How to Collect Your Sample

This test is a laboratory analysis performed on a sample that you collect yourself, usually at home, and then send to a certified laboratory. The lab measures specific markers in your sample and reports the results to you or your healthcare provider, who can interpret them in the context of your overall health and medical history.

The 24-hour urine ammonia test measures how much ammonia is in your urine over a 24-hour period. Ammonia is a waste product that comes from the breakdown of protein in your body. Your liver normally converts ammonia into urea, which your kidneys then filter out and excrete in urine. This test helps doctors see how well your body is processing and eliminating ammonia.

You may need this test to screen for a health condition before symptoms appear, to help identify the cause of symptoms you are currently experiencing, or to monitor a condition you already know you have. Your healthcare provider may also use it to check how well a treatment is working or to help guide decisions about your ongoing care.

Your doctor may order this test to: evaluate how well your kidneys are working, diagnose kidney disorders such as renal tubular acidosis, check for liver disease that affects ammonia processing, investigate certain metabolic disorders, or monitor conditions that impact ammonia metabolism in your body.

Your test kit includes detailed step-by-step instructions along with all the collection materials you need. In general, you will wash and dry your hands, use the provided container or collection device to obtain the sample exactly as directed, seal it securely, label it with your name and the date, and then follow the shipping instructions to send it to the laboratory promptly.

For a 24-hour urine collection: Start in the morning by urinating into the toilet and noting the exact time. Collect all urine for the next 24 hours in the provided container, keeping it refrigerated or in a cool place. If you need to have a bowel movement, collect any urine that passes as well. At the exact same time the next morning, urinate into the container one final time to complete the collection. Return the container to your lab as instructed.

Some tests require no special preparation, while others ask you to avoid certain foods, drinks, supplements, or medications for a short period before you collect your sample. Read the instructions in your kit carefully before you begin, and contact your healthcare provider if you take prescription medications and are unsure whether any of them could affect your results.

Before the test, tell your doctor about all medications you're taking. Avoid strenuous exercise during the collection period as it can affect results. Some foods and supplements may impact ammonia levels. Your doctor may ask you to avoid certain foods or fasting before the test. Follow any specific instructions provided by your healthcare team.