Proof of lactose intolerance is a method used to diagnose the ability of the intestines to break down lactose (milk sugar and its derivatives) when it is suspected that the substance is not digested well and causing discomfort. There are two types of tests lactose intolerance: one is performing a blood test to detect the presence of blood glucose before and after taking a preparation containing lactose; test and breath hydrogen by storage in special airtight bags for it, before and after taking a preparation containing lactose. The patient must be blowing in the containers and filling them with air to the time frequency that you select, while the automatic reaction of the preparation intake (increased abdominal size or other physical complaints, such as pain, spasms check ... ). Depending on the results of each phase, the test can be lengthened several hours. Subsequently, the hydrogen in the breath bags or containers will be analyzed for detailed diagnosis.