When was the last time you thought about breathing? Most people usually do not. When we are healthy, breathing happens naturally and easily. Without much effect on our part, the human respiratory system works hard. Experts say we take about 20,000 breaths every day. One such expert is James Hoyt, a doctor at the University of Colorado’s Health Pulmonology Clinic, also called UCHealth. Hoyt is a pulmonologist, a specialist on respiratory disorders. On the UCHealth website, he notes that our “respiratory muscles are working every minute of the day, every day of our lives.” A muscle called the diaphragm separates the chest and abdominal cavities. As we breathe in, the diaphragm tightens. The chest cavity opens, and the lungs expand. When we breathe out, the diaphragm relaxes and moves upward, pushing air out. When you breathe deeply, the air coming in through your nose fully fills your lungs, and the lower belly rises. On its website, Harvard Medical School notes that deep breathing may slow the heartbeat, lower blood pressure and lower stress. Deep breaths help your body fully exchange incoming oxygen with outgoing carbon dioxide.