Home > News Updated 22 November 2016 Health24 Health Challenge: Week 19 It's time for our weekly health challenge! Find out if you can score a perfect 10 on our quiz. 0 Joshua Carstens NEXT ON HEALTH24X Oil foils: your skin-care guide for acne-prone skin 2017-03-23 11:03 More: News advertisement Other news Lifestyle Oil foils: your skin-care guide for acne-prone skin Medical SEE: How long should a cough last? Medical Colonoscopy myths busted News Health24 Health Challenge: Week 33 Medical Two more arrests for ARV theft at Kanyamazane Clinic Medical SEE: How anaphylactic shock affects your body From our sponsors How to care for your vaginal flora Live healthier Hello? » SEE: Interesting facts about hearing loss Earworms: Let it go Is it bad to sleep with earplugs all the time? SEE: Do women hear better than men? The reason why men often appear not to be listening could be because they actually can't hear you. Confident smile? » Acidic drinks can harm your kids' smiles The facts on bleaching your teeth Am I taking good care of my teeth? Why are my teeth stained? We know the rules – brush your teeth twice a day and floss to keep them healthy. But, have you ever wondered what causes those stains that sometimes appear?