Insomnia can have many causes, such as stress, a specific sleep disorder or an underlying health condition, and can be difficult to manage. This is even more the case if insomnia continues over the long term. Most people will experience insomnia at some stage during their life time. However, if any of the following symptoms continue after a few days, it’s advisable not to ignore the condition, but to consult a doctor. Insomnia is a serious condition and can affect your physical and mental health.