Editing Lactose intolerance (section)

=== Lactose tolerance test ===
In conjunction, measuring blood glucose level every 10 to 15 minutes after ingestion will show a "flat curve" in individuals with lactose malabsorption, while the lactase persistent will have a significant "top", with a typical elevation of 50% to 100%, within one to two hours. However, due to the need for frequent blood sampling, this approach has been largely replaced by breath testing.<ref>{{cite web | url=http://www.webmd.com/digestive-disorders/hydrogen-breath-test | publisher=WebMD | title=Hydrogen Breath Test and Lactose Intolerance | access-date=2017-08-19 | url-status=live | archive-url=https://web.archive.org/web/20170816012411/http://www.webmd.com/digestive-disorders/hydrogen-breath-test | archive-date=2017-08-16 }}</ref>

After an overnight fast, blood is drawn and then 50 grams of lactose (in aqueous solution) are swallowed. Blood is then drawn again at the 30-minute, 1-hour, 2-hour, and 3-hour marks.  If the lactose cannot be digested, blood glucose levels will rise by less than 20&nbsp;mg/dl.<ref>{{cite web|url=https://www.nlm.nih.gov/medlineplus/ency/article/003500.htm|date=3 May 2011|title=Lactose tolerance tests|url-status=live|archive-url=https://web.archive.org/web/20160527051702/https://www.nlm.nih.gov/medlineplus/ency/article/003500.htm|archive-date=27 May 2016}}</ref>