Hypercapnia, which is an excessive level of carbon dioxide in the blood, can be a serious complication of respiratory fatigue. When the body experiences hypercapnia it needs to compensate for the increase in carbon dioxide so that its systems stay within normal ranges (Byrne et al. 2019). This compensation normally takes place through ventilation and respiration rate but there are other methods as well.

The most obvious method of compensating for increased CO2 levels is by increasing ventilation and respiration rate (Farr et al. 2018). If a person has difficulty breathing due to any underlying condition then this may not be possible without medical intervention. The body also has processes where it will try to reduce CO2 production by reducing activity or shifting metabolism away from using energy sources that produce more CO2 such as fats or proteins (Adler-Stepenscheidt & Linn 2016). Additionally, if a person experiences high levels of CO2 due to physical exhaustion then this may provide some temporary relief until they recover their strength.