The body language signs of stress

When a person gets stressed, they might start tapping on the floor with their legs or tapping with their hands on the table. 

Shaking one leg up and down repeatedly is one of the signs of stress in body language. While some people do this as a habit, others do it when they get stressed.

When a person gets stressed or frustrated, they might rub their face with one hand. This is usually an indication that the person is stressed and experiencing negative emotions.

Rubbing the back of the neck is a clear sign of frustration in body language. Because stress might be accompanied with frustration, a stressed person might rub their necks. 

Nail biting is a sign of stress and anxiety. When a person gets stressed and anxious, they might start biting their nails. (See Why some people bite their nails?)

When a person gets stressed, they might start sweating more. This can be noticed by the way their skins reflect light changes.

Stress can make the muscles more tense and thus the person's movements might be restricted. The person might also do many knee-jerk moves. 

Touching the nose in body language is a gesture that indicates the presence of negative thoughts. When a person gets stressed, they are more likely to think negatively and to have negative thoughts. (See Why do people touch their nose while speaking?)

When a person gets stressed, they are very likely to breath fast. This fast breathing rate can be noticed in the movement of the shoulders.

When a person gets stressed, they might scratch random body parts with their hands. This is a sign of both stress and frustration.