Apathy

• Apathy is one of the serious symptoms of fatigue. The patient is indifferent to everything that happens and has trouble making decisions.
  
  

Passing Out

• Passing out is not the same as falling asleep. It happens suddenly, when you do not expect it. People with fatigue associated with sleep disorders can pass out while driving a car or in the middle of reading a book.
  
  

Heart Palpitations

• Heart palpitations occur when the heart beats so fast you can feel and sometimes hear it. It could indicate an imbalance in electrolyte levels.
  
  

Vertigo

• Vertigo is the feeling that you, the world around you or both are moving, when in reality everything is still. It can be caused by decreased blood flow to the brain.
  
  

Shortness of Breath

• Shortness of breath can be caused by any number of respiratory conditions.