If a person says that he or she experiences sensory premonitions or warning signs like flashes of light and color that allow him or her to predict what is going to happen to his or her body, others may be slightly skeptical. They may think that description could apply to a character in the latest science fiction TV show or action hero movie, but they may have a harder time believing that a medical condition affecting millions of American could cause such symptoms. Although it may seem somewhat supernatural, many people can predict when they are going to have migraines based on prodromes (sensations of premonition) and auras (sensory warnings).

Migraines are severe, chronic headaches that are also accompanied by other symptoms, such as nausea and vomiting. Doctors do not fully understand how migraines work or what causes them. However, doctors do have theories to explain the science behind migraines, and they have identified some factors that make people more likely to get these headaches.

Approximately 29.5 million Americans suffer from migraines, which are repeated headaches that cause significant pain along with other symptoms. Migraine symptoms can be so severe that they prevent people from performing their normal, daily activities. Migraines often begin in childhood, adolescence, or early adulthood and affect people worse at younger ages.

The frequency of migraines varies from one person to another – some people may experience several migraines a month, while others may only experience a few per year. Each migraine attack typically lasts from four to 72 hours if it is not treated, but attacks can last longer than that. While there is no cure for migraines, medications can help reduce the frequency and severity of these headaches.

Migraine symptoms vary from person to person and can include some or all of the following:

• Moderate to severe pain, which can occur on one side of the head only or on both sides

• Head pain that pulses or throbs

• Head pain that worsens with physical activity

• Head pain that interferes with regular, daily activities

• Nausea

• Vomiting

• Sensitivity to light and sound

• Changes in vision, including blurred vision or blind spots

• Feeling tired and/or confused

• Feeling cold or sweaty

• Stiff or tender neck

•Tender scalp

• Light-headedness

Doctors do not completely understand what happens in the body during a migraine attack. However, according to one of the most popular theories, migraines occur as a result of blood flow changes in the brain. Researchers believe that people who suffer from migraines have a certain susceptibility to these headaches that may be genetic. This susceptibility makes their nervous systems (which include the brain, spinal cord, and nerves) respond differently to environmental triggers than nervous systems of people who do not suffer from migraines. This response causes blood flow changes in the brain that lead to migraines.

Environmental triggers that can start this process may include changing levels of the hormone estrogen in women, foods like alcohol and caffeine, missed meals, stress, sensory stimuli like bright lights or loud sounds, not enough sleep, too much sleep, intense physical exertion, changing weather or barometric pressure, and certain medications.

A person’s nervous system may respond to an environmental trigger in the following way to cause a migraine:

First, following exposure to some type of environmental trigger, some of the blood vessels leading to a person’s brain may constrict (or shrink). This reduces blood flow to the brain. Environmental triggers may cause blood vessels to constrict by triggering spasms in the blood vessels and/or by triggering the brain to release high levels of serotonin. Serotonin is a neurotransmitter (or a chemical messenger in the brain) that performs many roles for the body, including jobs related to pain regulation, mood regulation, and sleep induction. Examples of environmental factors that could affect levels of serotonin are certain foods and changing levels of the hormone estrogen in women.

Then, during the actual migraine attack, serotonin levels in the body drop. When serotonin levels drop, the trigeminal nerve (a nerve in the head that helps to relay sensory information, such as pain, to the brain) may release neuropeptides. Neuropeptides are chemical messengers sent out by neurons (the building blocks of the nervous system).

These neuropeptides cause the blood vessels leading to the brain to dilate (or widen). The expansion of these blood vessels can lead to inflammation in the surrounding tissues, which causes pain. Also, the dramatic changes in blood flow can trigger other symptoms, such as nausea and distorted vision.

Some people experience premonitions that let them know when they are about to have a migraine headache. These premonitions are called prodromes and can occur hours or even days before the actual migraine attack happens. Prodromes can include feelings of elation or intense energy, food cravings, thirst, fatigue, or mood changes like irritability or depression.

About one-fifth of people with migraines experience auras, which are sensory warning signs that occur closer in time to the actual migraine headache than prodromes. Symptoms of auras include visual disturbances (ex. blind spots and appearance of flashes, wavy lines, dots, or flashing lights), confusion, difficulty speaking, and tingling in the arms, legs, or face. Auras often occur less than an hour before the migraine attack begins, but they can also occur at the same time as the migraine attack. Doctors do not understand exactly what causes auras. However, they believe that auras may result from changes in nerve cell activity levels that move across the brain in a wave-like pattern.

People may experience prodromes, auras, both, or neither when they have migraines. Migraines preceded or accompanied by auras used to be called classic migraines but are now just called migraines with aura. Migraines not associated with auras used to be called common migraines but are now just called migraines without aura.

Millions of Americans suffer from migraines, which are severe, often debilitating headaches that are also accompanied by other symptoms, such as nausea, vomiting, and sensitivity to light and sound. If left untreated migraines typically last anywhere from a few hours to a few days. Some people are able to predict the onset of their migraines when they experience premonitions called prodromes and warning signs called auras.

Doctors are not sure exactly what causes migraines, but many believe that these headaches result when environmental factors (like stress and changing levels of estrogen in women) trigger changes in the flow of blood to the brain. Since estrogen levels seem to play some role in causing migraines and women have more estrogen than men, women are much more likely than men to experience migraines.

Although there is no cure for migraines, medications can help reduce the frequency and severity of migraines. If a person believes they may be suffering from migraines, he or she should make an appointment with a doctor.