Final answer:
The 35-year-old female may be experiencing anxiety or panic attacks, which can cause symptoms of pounding heart, shortness of breath, and sweating. It is recommended for her to seek medical evaluation to determine the underlying cause and receive appropriate treatment.
Step-by-step explanation:
The symptoms the 35-year-old female is experiencing, such as pounding heart, shortness of breath, and sweating, suggest she may be suffering from anxiety or panic attacks. These symptoms are commonly associated with these conditions and are triggered by situations such as taking the train or being in crowded places. It's important for her to seek medical evaluation to determine the underlying cause and receive appropriate treatment.