Tachypnea is defined as an elevated respiratory rate, or more simply, breathing that is more rapid than normal. A normal respiratory rate can vary depending upon age and activity, but is usually between 12 and 20 breaths per minute for a resting adult.
Tachypnea may occur with lung cancer when the body is not getting enough oxygen, either due to the tumor, other lung diseases such as COPD, or other medical conditions such as severe anemia. Tachypnea can also occur with anxiety, even when the body is getting enough oxygen.
Tachypnea often occurs along with dyspnea, the sensation of being short of breath.