Lugol's iodine is a special type of liquid that is used to help medical professionals check if you have enough iodine in your body. Iodine is a kind of chemical that our bodies need to stay healthy, and Lugol's iodine is a way to test if we have enough.
The liquid is made up of two main parts: iodine and potassium iodide. These two things together create a solution that is a dark brown color. Sometimes, Lugol's iodine is also called "iodine solution" because it is a mixture and solution is another way to say mixture.
When the doctor or nurse wants to check if you have enough iodine, they will ask you to swallow a tiny bit of the Lugol's iodine liquid. The liquid will move down into your stomach and get absorbed into your body. Then, the doctor will be able to tell if you have enough iodine in your body by looking at your urine or checking your blood.
Don't worry, the amount of Lugol's iodine you swallow is very small and won't hurt you. It's just a way for the doctor to make sure you are healthy and have all the nutrients your body needs to grow and be strong.