Migraines are severe, chronic (recurring) 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. This coupled with the fact that migraine symptoms vary from person to person and the fact that there are different types of migraines makes it difficult for doctors to diagnose migraines. Typically, doctors use information about a patient’s family medical history and symptoms to diagnose this condition. However, they may also need to rule out other causes of headaches and other types of headaches before giving a patient a diagnosis of migraines. Because of the difficulties associated with migraine diagnoses, many people are undiagnosed or incorrectly diagnosed, which may mean that they are not receiving the proper treatment.

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. These symptoms vary from person to person but can include moderate to serve pain that occurs on one side of the head or both sides, head pain that pulses or throbs, nausea, vomiting, sensitivity to light and sound, changes in vision (blurred vision), and lightheadedness.

Some people who experience migraines experience premonitions called prodromes (fatigue or mood changes) hours or days before a migraine attack. People with migraines can also experience auras, which are sensory warning signs that often occur less than an hour before the migraine attack begins. Symptoms of auras include visual disturbances (blind spots and appearance of flashes, wavy lines, dots, or flashing lights), confusion, difficulty speaking, and tingling in the arms, legs, or face. People may experience prodromes, auras, both, or neither when they have migraines.

Migraines often begin in childhood, adolescence, or early adulthood and affect people most severely at younger ages. Women are also three times more likely to experience migraines than men are. This may be because estrogen (a chemical produced in the ovaries that is involved in the female reproductive cycle) affects levels of serotonin, a chemical thought to play a role in causing migraines.

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.

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.

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:

Following exposure to an 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.

Then, during the actual migraine attack, serotonin levels in the body drop. When serotonin levels drop, chemicals are sent out that 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.

Types of Migraines

Doctors have identified two main types of migraine headaches – migraine with aura and migraine without aura.

Migraine with Aura (previously called classical migraine): Approximately one-fifth of people with migraines experience auras (sensory warning signs including visual disturbances, confusion, difficulty speaking, and tingling in the arms, legs, or face). While auras often appear less than an hour before a migraine attack begins, they can also occur at the same time as the migraine attack. Aura symptoms typically last between 15 minutes and an hour, and the most common symptoms are visual disturbances.

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.

Migraine without Aura (previously called common migraine): Most people who suffer from migraines experience migraines without auras. These migraine attacks can develop more slowly than migraines with auras. However, once the migraine attacks begin, the symptoms of migraines without auras and migraines with auras are similar (ex. throbbing head pain, nausea, vomiting, sensitivity to light and sound, etc.).

Migraines without auras can also evolve into chronic migraines. People can be diagnosed with chronic migraines if they meet both of the following criteria:

Experience headaches that are not caused by some other medical condition on at least 15 days a month for at least three months.

Experience two or more of the following symptoms on at least eight days a month for at least three months: pain on only one side of the head, pulsating head pain, head pain that is moderate to severe, and head pain that gets worse after physical activity. These symptoms also need to lead to one of the following on those eight or more days a month for three or more months: nausea, vomiting, or sensitivity to light and sound.

Note: If people take medications in anticipation of these symptoms on at least eight days a month for at least three months and thus do not experience the symptoms, they can also be diagnosed with chronic migraines.

The variability in migraine symptoms and triggers from person to person, the variability in symptoms from one migraine attack to the next in the same person, and the fact that doctors do not fully understand what causes migraines make it difficult for doctors to diagnose patients with the condition. Thus, doctors use a variety of methods to diagnose migraines including the following:

Collect the Patient’s Medical History: If a patient goes to see a doctor and reports symptoms that could be caused by migraines, the doctor will first collect information about that patient’s medical history. Doctors believe that there is a genetic component to migraines, so a doctor will ask a patient if anyone else in his or her family suffers from migraines.

Also, the doctor will ask questions about the patient’s headaches, such as when the patient first started experiencing them, how frequently they occur, how long they last, what symptoms the patient experiences, what seems to cause the headaches, and whether or not the headaches interfere with the patient’s daily activities. Based on information about the patient’s headaches, doctors can determine if a diagnosis of migraines is a possibility or if it is likely that the headaches are being caused by some other condition.

Conduct a Physical Exam and a Neurological Exam: After collecting information about the patient’s family history and headaches, a doctor will perform a physical exam and a neurological exam to check for symptoms of other conditions that may be causing the headaches. For example, during the physical exam, the doctor will check for symptoms, such as fever and breathing abnormalities that could indicate the patient has some type of infection. In a neurological exam, a doctor will assess a patient’s sensory and motor abilities, hearing and speech, vision, and coordination and balance. Using this information, the doctor will try to rule out conditions like epilepsy (a disorder that causes seizures) and multiple sclerosis (an autoimmune disease that affects the functioning of the nervous system) as causes of the patient’s headaches.

After a doctor collects a patient’s medical history and performs a physical and a neurological exam, he or she may give the patient a diagnosis of migraines (or of some other condition depending on the results of the exams). However, sometimes doctors need to use additional diagnostic tests to rule out other conditions that could cause headaches. Examples of these tests include:

Blood Chemistry and Urinalysis. These tests help a doctor rule out conditions such as diabetes, thyroid problems, and certain infections that may be triggering a patient’s headaches.

Computerized Tomography (CT scan): In a CT scan, a doctor uses computer-directed x-rays to look at a cross-sectional view of the patient’s brain. By looking at this view of the brain, a doctor can make sure that a patient does not have a tumor or an infection that may be causing his or her headaches.

Magnetic Resonance Imaging (MRI): During an MRI, a doctor uses radio waves and a powerful magnet to look at detailed cross-sectional views of a patient’s brain. Doctors can use MRIs to examine the blood vessels leading to the brain to see if they can see anything there that may explain a patient’s headaches. Also, doctors use MRIs to rule out tumors, strokes, aneurysms, neurological diseases, and other brain abnormalities as causes of a patient’s headaches.

Spinal Tap (lumbar puncture): During this procedure, a doctor extracts a sample of fluid (called cerebrospinal fluid) from between a patient’s vertebrae. Analyzing this cerebrospinal fluid can allow a doctor to rule out conditions including meningitis (an inflammation of the membranes surrounding the brain and spinal cord).

Eye Exam: During this test, an eye doctor makes sure that a patient’s headaches are not caused by glaucoma (a disease where the nerve leading from the eye to the brain becomes pressured or damaged, possibly because of elevated fluid pressure within the eyeball).

In addition to ruling out other conditions that could be causing a patient’s headaches, a doctor also needs to make sure that the patient’s headaches are truly migraine headaches instead of some other type of headache. Other types of headaches include the following:

Tension (or sinus) Headaches. Tension headaches are the most common type of headache. A patient may mistake tension headaches for migraine headaches for several reasons. Symptoms of both types of headaches can include pain on both sides of the head and tenderness on the scalp. Also, both types of headaches can be triggered by stress and fatigue, can occur often or infrequently, and can last for a few hours or for days.

Although there are similarities between tension headaches and migraines, there are also differences. For example, tension headaches are less painful and debilitating than migraines. The pain in tension headaches is also often steady, while the pain in migraine headaches is typically throbbing. Additionally, migraines can be triggered by certain foods, levels of estrogen, and changes in the weather, while tension headaches cannot. Finally, tension headaches usually do not cause symptoms such as visual disturbances, nausea, vomiting, and speech difficulties the way that migraines do. By listening to a patient’s description of his or her headache symptoms, a doctor will be able to tell if that patient may be experiencing tension headaches instead of migraines.

Cluster Headaches. This rare type of headache is characterized by attacks that occur in cyclical patterns (or clusters). A person may experience frequent attacks over a period of weeks or months and then may not experience any attacks at all during the next few months. A patient may mistake cluster headaches for migraines because cluster headaches are painful, may be accompanied by auras, and can cause symptoms, such as nausea and sensitivity to light and sound, which are also characteristic of migraines.

However, there are differences in the symptoms of cluster headaches and migraines as well. For example, cluster headaches typically cause pain around one eye. Also, cluster headache pain is usually described as sharp, penetrating, or burning as opposed to throbbing. Based on a patient’s headache symptoms, a doctor can determine if the headaches are cluster headaches instead of migraines.

Improving the Accuracy of Migraine Diagnoses

Diagnosing migraines is difficult because people experience varying symptoms and triggers of migraines, there are different types of migraines, and doctors do not fully understand what causes the condition. Although doctors have several techniques for diagnosing migraines ranging from collecting patients’ medical histories to performing diagnostic tests like CT scans and MRIs, many people with migraines remain undiagnosed or misdiagnosed. This is problematic because if people are not diagnosed correctly, they cannot be treated correctly. However, by keeping track of the symptoms and triggers of their headaches, people who believe that they have migraines can give their doctors information that can help increase the accuracy of their diagnoses.