Occasional and temporary disturbance of one's regular sleeping pattern is normal and not cause for concern – stress, worry or excitement are common causes, and generally normal sleeping habits return when the cause is resolved.
Sleeping patterns may also be disrupted by changes in routine – for example international travel, changes in working hours, or sleeping in a different environment to the one you’re used to.
Environmental factors such as noise, light or poor ventilation may also contribute to insomnia.
Amongst the many physical ailments that can interfere with your sleep are disorders of the cardiovascular, respiratory, urinary, digestive, endocrine and nervous systems. It is also common for conditions associated with chronic pain to cause insomnia.
The sleep disorder sleep apnoea may cause disturbed sleep by obstructing the airways, forcing you to wake up repeatedly during the night in order to obtain enough oxygen. Sleep apnoea is associated with being overweight, drinking alcohol, taking sleeping tablets, and having nasal or sinus problems. It may increase the risk of cardiovascular disease and other health problems, so if you are concerned that you or your partner may be affected, it is important that you talk to your doctor.
Insomnia, sometimes in conjunction with night sweats, can also be one of the symptoms of menopause. In men, it may occur if benign prostatic hypertrophy (BPH) causes the need for frequent night-time urination.
Caffeine, alcohol, nicotine and certain drugs may also increase the likelihood of developing insomnia. Examples include some blood pressure medications, nasal decongestants and certain recreational drugs.