It has long been believed that morning headaches are caused by a range of different sleep disorders and while this is undoubtedly true it does not paint a complete picture. For example, it is also now known that morning headaches are commonly seen in people who are either underweight or overweight, those suffering from a range of conditions including musculoskeletal, heart and respiratory disease as well as people who regularly drink more than about 6 glasses of alcohol a day or who take anti-anxiety, antidepressant, hypnotic or neuroleptic medicines. Interestingly enough however there is no indication of any link between morning headaches and smoking.