Final answer:
The proper treatment for the woman experiencing fainting and other symptoms in small spaces or crowds is likely psychological therapy like Exposure Therapy or Cognitive Behavioral Therapy, after ruling out underlying medical conditions.
Step-by-step explanation:
The best treatment for the 20-year-old woman who experiences fainting spells, dizziness, nausea, and difficulty breathing when in small spaces or crowds, yet is not scared of open spaces or public transport, may be related to a psychological condition such as claustrophobia. The details provided in the scenario suggest that her symptoms are triggered by specific situations rather than a physiological condition such as asthma or anemia, which might present with similar symptoms but would be more persistent across various situations and not solely triggered by enclosed spaces or crowds.
Therefore, for this patient, the appropriate course of action would likely be psychological therapy, specifically Exposure Therapy or Cognitive Behavioral Therapy (CBT). These therapies help patients gradually face and desensitize to the fear associated with certain situations. Additionally, anxiety-reducing medications could be considered as a temporary aid or in combination with therapy. It is important, however, that the patient undergo a thorough medical evaluation to rule out any potential underlying medical conditions before proceeding with a psychological treatment plan.