Bad breath and body odour can also be sign of stress and psychological strain. On the one hand, a nervous stomach and chronic gastritis can be typical consequences of constant stress.
On the other hand, people’s eating habits change when they are under stress. Someone suffering from stress eats too little and too quickly. In addition, they mostly eat fast food which particularly delights the bacteria in the mouth. They also don’t have enough time to maintain a thorough oral hygiene routine.
Another important correlation: With any excitement, stress hormones inhibit the production of saliva (“My mouth is drier than the Sahara!”) and cause an imbalance in the oral flora. The same hormones can also increase the production of sweat, an effect that everyone who has ever taken an exam will be familiar with.