1. Initiation of exercise
As exercises initiate with muscle mobilization and contraction, there is a demand for more oxygen from the body, which causes an increase in respiratory rate and depth to allow more and sufficient oxygen into the lungs.
2. Moderate exercise
As exercise becomes more intense, carbon dioxide levels and oxygen demand increase, leading to a continuous increase in respiratory rate and depth. This is to achieve sufficient oxygen entering the lungs and omitting carbon dioxide.
3. Abrupt ascent into high altitudes
Places with higher altitudes come with less oxygen availability, causing respiratory difficulties such as reduced oxygen content in the blood and breathing instability. Due to insufficient oxygen sources, the body initiates increased respiratory rate and depth to increase oxygen content entering the body.
4. Paralysis of phrenic nerve
The phrenic nerve serves a pivotal role in respiration as it controls the contraction of the diaphragm, which takes part in breathing capability. Paralysis of this nerve will lead to diaphragm malfunction, causing breathing instability or problems due to the restriction of gas exchange needed by the body.
5. Severe anemia
As anemia disables blood to carry sufficient oxygen content, respiratory difficulties such as hyperventilation as initiation of increased respiratory rate and depth happen.
6. Advanced Pregnancy
Pregnancy causes increased respiratory resistance, reduced respiratory conductance, and the fetus compresses the diaphragm of the carrier (leading to reduced lung volume). Due to these respiratory considerations, increased ventilation happens to cater oxygen demand for both the fetus and the mother.