nausea itself is a very non-specific symptom and could result from GI infection/ inflammation, micronutrient deficiencies, GI motility issues, o non-GI causes such as stress/ anxiety, hormonal/ endocrine imbalances, metabolic issues, micronutrient deficiencies,
medication side effect etc. Management in most cases would depend on the underlying cause and usually a detailed evaluation by an internist would be suggested for an accurate diagnosis and appropriate management.
Hope this is helpful.