The majority of people experience extreme fatigue and many suffer post-stress discomfort, a kind of energy crash. Brain fog, lack of concentration and memory loss are also common symptoms.

Some people develop conditions and syndromes such as postural orthostatic tachycardia syndrome (POTS), characterized by dizziness and palpitations when a person is in a upright position. Others develop dysautonomia, which causes palpitations, pressure rises or falls, dizziness and gastric problems.