You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is In COPD w hich is true - and explain in detail?
Ans. is 'a' i.e., FEV1 / FVC < 0.7 The lung function tests in obstructive lung disease can be summarized as -o Forced expiratory vital capacity (FEVc)- Normal to slightly decreasedo Forced expiratory volume in 1 secQ (FEV )-Decrease out of proportion to FVCo FEV1/FEV1Q-Decrease can be as low as 20% - 30%o Peak expiratory flow rate-Decreasedo Total lung capacity-Increaseo Residual volume-Increaseso Functional residual capacity-Higher