The symptoms of stress are many and varied, such as:
Irritability
Headaches
Illness
Insomnia
Tiredness/lethargy
Sometimes, you can be experiencing stress but your mind and body are so good at hiding it from you that you are unaware of it. In such cases the symptoms, such as:
Working endlessly without tiring
Having little feeling or emotion (except the occasional outburst of anger)
Increased use of alcohol/cigarettes
Use of drugs
Behave abnormally
If you are under a lot of stress for a period of time, it may cause more serious problems, such as:
Stomach ulcers
Heart problems
Minor illness (allergies, skin disorders, migraine)