The more common of these conditions include: various anxiety disorders, asthma, hyperventilation, pneumonia, pulmonary edema, and shock. Anxiety, stress, and panic attacks often accompany shallow breathing.
If u mean the endocrine system .The endocrine system is the collection of glands of an organism that secrete hormones directly into the circulatory system to be carried towards distant target organs.
It's very common in early pregnancy for any symptoms to fluctuate from one day to the next. One day you might feel completely exhausted, only to feel fresh and re-energised the following day.
(Hope this helps!)
