You may need to do an acid loading test if your doctor thinks your kidneys are not doing their job properly and your blood is too acidic as a result. This can cause a disease called renal tubular acidosis, which can slow down how fast you grow and cause many other symptoms like making you feel weak.

You will first have to take a special medicine for 3 days called ammonium chloride. This medicine comes in capsules and it will make your blood a little more acidic than it usually is. Then after 3 days you will have to go to your doctor’s office to do a blood and a urine test.

You should make sure you wash your genitals (penis or vagina) before doing a wee for your urine test. This is so the wee doesn’t pick up any germs or dirt from your skin. If any germs or dirt get in, it could spoil the results of the test. If you have to wash before a urine test it’s called a clean-catch urine test.

A blood test will be done to collect a blood sample. This will probably be taken from one of the veins in your arm, or possibly from your wrist or the back of your hand. The doctor or nurse will clean your skin over the veins and then put a needle in to take the sample.

For your urine test your doctor will give you a small, plastic container to wee into. You should start by weeing into the toilet for a bit, and then collect the middle part of your wee in the container. After you have finished, wash your hands properly and give the container back to your doctor.

When you have your blood test you will just feel a tiny prick when the needle goes in but it shouldn’t hurt very much. If you don’t like needles and injections, tell the person who is taking the sample, so that they can help you to relax. If you feel like you are going to faint, you should tell the person who is doing the test and they will get you to lie down until you feel better.

A urine test doesn’t hurt at all.

Your blood and urine samples are sent to a lab where they are tested to see how acidic your wee is compared to your blood. Your blood should be a bit acidic from the medicine you took. If your kidneys are working well, your wee should also be a little bit acidic. Your doctor will probably get the results back within a couple of weeks, and will then explain to you exactly what they mean.

If you have any other questions, you can ask your doctor, or chat to other people about the acid loading test in the Medikidz forums and virtual world, Mediland.