Weather is a common trigger of migraine headaches. Review of studies linking weather to migraines suggests that there are three weather-related triggers. It is high humidity, high temperature, and drop in barometric pressure. Some migraine sufferers, just like many people with arthritis, can predict rainy weather. We can speculate that the drop in barometric pressure causes blood vessels inside the skull to dilate and trigger a migraine. This happens because of faulty regulation of blood vessels in those with migraine. This is also probably the reason why migraines are sometimes caused by exercise or sexual activity – blood vessels dilate excessively and trigger a migraine. High altitude headache or mountain sickness is another example of headaches caused by low barometric pressure. In fact, one study showed that people living at high altitudes, specifically in Denver, are more likely to have mgraines than those living at sea level. Treatment of barometric pressure headaches involves the usual approaches to migraines – regular exercise, biofeedback, magnesium, CoQ10, Botox, and drugs. Diamox (acetazolamide) is a diuretic drug that is particularly effective for mountain sickness and in some patients can also prevent weather-related headaches.
It is not clear why high humidity causes headaches, but high temperature may lead to a) dehydration, which is a trigger of migraines for many and b) again, dilatation of blood vessels which the body uses to cool itself by bringing more warm blood to the surface (this is why we look red in the heat).
There is an easy way to figure out if your headaches are triggered by weather – download our free app into your iPhone or iPad. Headache Relief Diary (also known as Migralex Diary) automatically downloads barometric pressure, humidity and temperature at the time of your headache. Just enter your zip code once and enter your headache information every time you get one and after a month or two you may be able to find your migraine triggers, including those related to the weather.

Headache is one of the most common complaints reported by patients suffering from AIDS, according to a new study by researchers from the University of Alabama. They evaluated 200 patients with HIV/AIDS and discovered that 107 or 54% of them had headaches. Only 4 of these patients had a serious underlying cause, while 88, or 44% had migraines and the rest had tension-type headaches. This is a much higher incidence of migraines than in the general population, where only 12% have migraines. The severity of HIV (CD4 cell count) correlated with the headache severity, frequency, and disability. The findings of this study suggest the importance of diagnosing and treating migraines in this population which already has reduced quality of life and which migraines make even worse.

Smoking by the mother during pregnancy increases the risk that the child will suffer from headaches. Brazilian researchers published results of their study in the journal Cephalalgia. They collected information on over 1,600 children aged 10 – 11 years and discovered that children of mothers who smoked 10 or more cigarettes a day were more likely to suffer from tension or migraine headaches. Surprisingly, exposure to second-hand smoke was not associated with an increased risk of headaches in children.

Depression is more likely to occur in people with migraines, but migraines are also more likely to develop in those who suffer from depression first. A new Canadian study reexamined this link in 15,254 people. They confirmed this association, but unlike in previous studies the researchers from Calgary discovered that this bi-directional relationship is symmetrical. That is, if you have migraines you are 80% more likely to develop a major depressive episode, but if suffer from depression first, you are only 40% more likely to develop migraines. They found that childhood trauma and stress may be a contributing factor to both conditions. The authors of the study discuss the fact that common genetic abnormalities may also predispose people to both conditions.

Genetic analysis of 594 members of 134 families by Spanish researchers confirmed the results of a previous study that discovered a genetic abnormality on the sixth chromosome that seems to be associated with migraines. This genetic marker is present only in a small proportion of migraine sufferers, but it is very likely that there are several or many other genetic abnormalities that predispose to migraine. In patients with familial hemiplegic migraine very specific genes have been identified, but even in this rare form of migraine different families had different genes that were abnormal. This wide variety of genetic factors will make it difficult to develop genetic therapies for migraine, when such therapies become available (probably 10 or more years from now). However, people who have genetic abnormalities are only predisposed to having migraines, but not necessarily will have them. This predisposition makes it more likely that the person will develop migraines, however, avoiding triggers and improving general health may prevent or at least reduce the frequency and the severity of attacks.

Women who suffer from both episodic and chronic migraines are more likely to have widespread chronic pain, which is often diagnosed as fibromyalgia. Brazilian researchers evaluated 179 women with episodic and chronic migraine. They discovered that the more frequent were their migraine attacks, the more likely they were to have widespread chronic pain. A likely explanation of this association is the phenomenon of allodynia. Allodynia is an increased sensitivity of the skin during and after a migraine attack, which affects many migraine sufferers. Patients often report not being able to brush their hair or wear glasses because the skin becomes very sensitive. This skin sensitivity can spread from the face and scalp to involve the upper body. It is logical to assume that with frequent migraine attacks this sensitivity spreads and can involve the entire body. This sensitivity is is a reflection of increased excitability of brain cells, which has been documented to be present in migraine sufferers. If migraines are frequent and are left untreated, this increased excitability can become persistent and may predispose to other chronic pain conditions. The obvious important lesson of this study is that migraine headaches need to be treated aggressively in order to avoid the development of additional pain syndromes and impaired quality of life. This treatment should utilize all available approaches – abortive drugs such as triptans (as well as Migralex and NSAIDs), and prophylactic therapies, including aerobic exercise, biofeedback, magnesium, CoQ10, Botox injections and prophylactic drugs.