Why do l yawn when i'm not tired?

Need for oxygen.: A yawn implies that your body needs more oxygen at that moment, and your brain triggers a gigantic inhalation, i.e. a yawn. During exercise, for example, you might need more oxygen in a moment than your body can deliver, so you yawn. So to generalize, at the moment you’re yawning your body would seem to need more oxygen for some reason.

Surfactant: A lipid moiety that normally coats the alveloli of the lungs, surfactant, needs periodic expansion of the lung to maintain optimal function. The deep inspiration may be in the form of a yawn or a sigh. Wish you good health! - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex, if you have sex.