Significant changes in life such as a separation from a partner, the loss of a near and dear person and life-changing events such as retirement or children leaving home can be causes for an adjustment disorder. In cases such as these you may experience extreme stress and may not be able to cope.
Something similar to a depression or symptoms of anxiety might arise along with physical discomforts such as stomach ache, tension or cardiovascular complaints. Quite often, the ability to concentrate is affected. Many react with social retreat.
A traumatic experience can lead to enduring and disturbing reactions such as those mentioned above. The condition is commonly known as Post traumatic stress disorder.