A headache in the morning after waking up is usually related to sleep disorders. Clinical studies have confirmed that sleep apnea and snoring may lead to morning headaches. Some other studies reported the connection between the headache and periodic limb movement disorders. Typically these kinds of headaches are related to hypertension. One study was conducted in order to establish the status of mental disorders in case of morning headaches. This two stage-study included 5 European countries. The population was separated according to geographical distribution. There were 18.980 participants and the Kish method (17) was used to keep the representation of the sample and evade related prejudice related to non-coverage error. This study tried to find relationship between headaches in the morning after waking up and the following factors: socio-demographic determinants, usage of psychoactive substances, organic disorders and sleep and/or mental disorders.
As for socio-demographic determinants, the results were related to gender, age and work. Women, middle aged people and unemployed or housewives were affected most.
The correlation between heavy drinking and morning headaches was quite clear. This also included the usage of anxiolytic drugs.
As for organic disorders people who suffered from hypertension or musculo-skeletal diseases had a bigger risk of reporting the headaches. Typically headaches due to hypertension tend to occur in the morning. But this factor was not representative since generally if a person suffers from hypertension this does not mean he/ she will have headache in the morning or if a person do experience headache in the morning this does not mean he/ she is suffering from hypertension. Obstructive Sleep Apnea Syndrome prevents the air to reach the lungs and this result in hypoxia. This shortage of oxygen may lead to headaches on awakening. In this study the findings regarding the influence of sleep breathing disorders (Obstructive Sleep apnea Syndrome in particular) were non-specific.
Other sleep disorders that were investigated were dyssomnia and sleep disorders with multiple possible causes. In this case an obvious explanation was that these disorders led to morning headaches due to lack of sleep caused by sleep deprivation.
People who suffered from depression experienced headaches more than others. This as well as many other studies tried to find the link between these two conditions and the conclusion was that people suffering from headaches on awakening were more prone to developing the major depression.
The conclusion was that the causes of the headaches on awakening were organic diseases or mental disorders rather than other possible culprits such as socio-demographic determinants or usage of anxyolitic drugs. If the morning headaches tend to recur they are in 80% related to organic, mental or sleep disorders.