All people who present with red flags indicating a dangerous secondary headache should receive neuroimaging. The best form of neuroimaging for these headaches is controversial. Non-contrast computerized tomography (CT) scan is usually the first step in head imaging as it is readily available in Emergency Departments and hospitals and is cheaper than MRI. Non-contrast CT is best for identifying an acute head bleed. Magnetic Resonance Imaging (MRI) is best for brain tumors and problems in the posterior fossa, or back of the brain. MRI is more sensitive for identifying intracranial problems, however it can pick up brain abnormalities that are not relevant to the person's headaches.

The American College of Radiology recommends the following imaging tests for different specific situations:

A lumbar puncture is a procedure in which cerebral spinal fluid is removed from the spine with a needle. A lumbar puncture is necessary to look for infection or blood in the spinal fluid. A lumbar puncture can also evaluate the pressure in the spinal column, which can be useful for people with idiopathic intracranial hypertension (usually young, obese women who have increased intracranial pressure), or other causes of increased intracranial pressure. In most cases, a CT scan should be done first.

Cluster headache may be misdiagnosed as migraine or sinusitis. Other types of headache are sometimes mistaken for, or may mimic closely, CH. Incorrect terms like "cluster migraine" confuse headache types, confound differential diagnosis and are often the cause of unnecessary diagnostic delay, ultimately delaying appropriate specialist treatment.

Headaches that may be confused with CH include:

- Chronic paroxysmal hemicrania (CPH) is a unilateral headache condition, without the male predominance usually seen in CH. Paroxysmal hemicrania may also be episodic but the episodes of pain seen in CPH are usually shorter than those seen with cluster headaches. CPH typically responds "absolutely" to treatment with the anti-inflammatory drug indomethacin where in most cases CH typically shows no positive indomethacin response, making "Indomethacin response" an important diagnostic tool for specialist practitioners seeking correct differential diagnosis between the conditions.

- Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) is a headache syndrome belonging to the group of TACs.

- Trigeminal neuralgia is a unilateral headache syndrome, or "cluster-like" headache.

Cluster headaches are often misdiagnosed, mismanaged, or undiagnosed for many years; they may be confused with migraine, "cluster-like" headache (or mimics), CH subtypes, other TACs ( trigeminal autonomic cephalalgias), or other types of primary or secondary headache syndrome. Cluster-like head pain may be diagnosed as secondary headache rather than cluster headache.

A detailed oral history aids practitioners in correct differential diagnosis, as there are no confirmatory tests for CH. A headache diary can be useful in tracking when and where pain occurs, how severe it is, and how long the pain lasts. A record of coping strategies used may help distinguish between headache type; data on frequency, severity and duration of headache attacks are a necessary tool for initial and correct differential diagnosis in headache conditions.

Correct diagnosis presents a challenge as the first CH attack may present where staff are not trained in the diagnosis of rare or complex chronic disease. Although experienced ER staff are sometimes trained to detect headache types, CH attacks themselves are not directly life-threatening, they are linked to an increased risk of suicide.

Individuals with CH typically experience diagnostic delay before correct diagnosis. People are often misdiagnosed due to reported neck, tooth, jaw, and sinus symptoms and may unnecessarily endure many years of referral to ear, nose and throat (ENT) specialists for investigation of sinuses; dentists for tooth assessment; chiropractors and manipulative therapists for treatment; or psychiatrists, psychologists and other medical disciplines before their headaches are correctly diagnosed. Under-recognition of CH by health care professionals is reflected in consistent findings in Europe and the United States that the average time to diagnosis is around seven years. Medical students receive little training in differential diagnoses and management of headaches.

The diagnosis of a migraine is based on signs and symptoms. Neuroimaging tests are not necessary to diagnose migraine, but may be used to find other causes of headaches in those whose examination and history do not confirm a migraine diagnosis. It is believed that a substantial number of people with the condition remain undiagnosed.

The diagnosis of migraine without aura, according to the International Headache Society, can be made according to the following criteria, the "5, 4, 3, 2, 1 criteria":

- Five or more attacks—for migraine "with" aura, two attacks are sufficient for diagnosis.

- Four hours to three days in duration

- Two or more of the following:

- Unilateral (affecting half the head);

- Pulsating;

- Moderate or severe pain intensity;

- Worsened by or causing avoidance of routine physical activity

- One or more of the following:

- Nausea and/or vomiting;

- Sensitivity to both light (photophobia) and sound (phonophobia)

If someone experiences two of the following: photophobia, nausea, or inability to work or study for a day, the diagnosis is more likely. In those with four out of five of the following: pulsating headache, duration of 4–72 hours, pain on one side of the head, nausea, or symptoms that interfere with the person's life, the probability that this is a migraine is 92%. In those with fewer than three of these symptoms the probability is 17%.

Preventive treatments of migraines include medications, nutritional supplements, lifestyle alterations, and surgery. Prevention is recommended in those who have headaches more than two days a week, cannot tolerate the medications used to treat acute attacks, or those with severe attacks that are not easily controlled.

The goal is to reduce the frequency, painfulness, and/or duration of migraines, and to increase the effectiveness of abortive therapy. Another reason for prevention is to avoid medication overuse headache. This is a common problem and can result in chronic daily headache.

MAV is not recognized as a distinct diagnostic entity. Lembert and Neuhauser propose criteria for definite and probable migraine-associated vertigo.

A diagnosis of "definite migraine-associated vertigo" includes a case history of:

- episodic vestibular symptoms of at least moderate severity;

- current or previous history of migraine according to the 2004 "International Classification of Headache Disorders";

- one of the following migrainous symptoms during two or more attacks of vertigo: migrainous headache, photophobia, phonophobia, visual or other auras; and

- other causes ruled out by appropriate investigations.

A diagnosis of "probable migraine-associated vertigo" includes a case history of episodic vestibular symptoms of at least moderate severity and one of the following:

- current or previous history of migraine according to the 2004 "International Classification of Headache Disorders";

- migrainous symptoms during vestibular symptoms;

- migraine precipitants of vertigo in more than 50% of attacks, such as food triggers, sleep irregularities, or hormonal change;

- response to migraine medications in more than 50% of attacks; and

- other causes ruled out by appropriate investigations.

Note that, in both of the above criteria, headache is not required to make the diagnosis of migraine-associated vertigo.

They add that, in patients with a clear-cut history, no vestibular tests are required. Other historical criteria which are helpful in making the diagnosis of migraine-associated vertigo are vertiginous symptoms throughout the patient’s entire life, a long history of motion intolerance, sensitivity to environmental stimuli, illusions of motion of the environment, and vertigo that awakens the patient.

Prenatal screening is not typically done for FHM, however it may be performed if requested. As penetrance is high, individuals found to carry mutations should be expected to develop signs of FHM at some point in life.

Treatment of migraine-associated vertigo is the same as the treatment for migraine in general.

"See the equivalent section in the main migraine article."

People with FHM are encouraged to avoid activities that may trigger their attacks. Minor head trauma is a common attack precipitant, so FHM sufferers should avoid contact sports. Acetazolamide or standard drugs are often used to treat attacks, though those leading to vasoconstriction should be avoided due to the risk of stroke.

Most patients have persistent headaches, although about 15% will remit, and 8% will have a relapsing-remitting type. It is not infrequent for NDPH to be an intractable headache disorder that is unresponsive to standard headache therapies.

As of 2013 tension headaches affect about 1.6 billion people (20.8% of the population) and are more common in women than men (23% to 18% respectively). Despite its benign character, tension-type headache, especially in its chronic form, can impart significant disability on patients as well as burden on society at large.

Although the original Silberstein–Lipton criteria and the original description by Vanast make no suggestion for the exclusion of migrainous features in NDPH, the current ICHD criteria exclude patients with migrainous features. When migraine features are present, classification thus becomes problematic.

It has been reported that migraine symptoms may be present in over 50% of NDPH patients. The current criteria definition thus excludes more than half of patients with new onset of daily headache. This exclusion due to migrainous features could have adverse scientific, diagnostic, and treatment consequences.

One proposal for reclassification of the criteria is from a study conducted on retrospective analysis of the records of 1348 patients regularly treated at the headache clinic of the Department of Neurology of Santa Casa de São Paulo, Brazil, and would be the following subdivision: NDPH with migraine features and without migraine features that would allow the inclusion of all individuals present who has a daily and persistent headache from the beginning.

Another proposed reclassification of the criteria is from a study conducted as a retrospective chart review of patients seen at the Headache Center at Montefiore Medical Center in Bronx, New York, from September 2005 to April 2009. The revised criteria for NDPH definition does not exclude migraine features (NDPH-R), and three subdivisions were created and described based on prognosis: Persisting, remitting, and relapsing–remitting. Additionally, this revised criteria would not include parts C or D currently required by the ICHD diagnostic criteria for NDPH.

The prevention and treatment of acephalgic migraine is broadly the same as for classical migraine, but the symptoms are usually less severe than those of classic migraine, so treatment is less likely to be required.

Drinking water and avoiding dehydration helps in preventing tension headache. Using stress management and relaxing often makes headaches less likely. Drinking alcohol can make headaches more likely or severe. Good posture might prevent headaches if there is neck pain. People who have jaw clenching might develop headaches, and getting treatment from a dentist might prevent those headaches. Biofeedback techniques may also help.

Treatment depends on identifying behavior that triggers migraine such as stress, sleep deprivation, skipped meals, food sensitivities, or specific activities. Medicines used to treat retinal migraines include aspirin, other NSAIDS, and medicines that reduce high blood pressure.

Acephalgic migraines can occur in individuals of any age. Some individuals, more commonly male, only experience acephalgic migraine, but frequently patients also experience migraine with headache. Generally, the condition is more than twice as likely to occur in females than males. Pediatric acephalgic migraines are listed along with other childhood periodic syndromes by W.A. Al-Twaijri and M.I. Shevell as "migraine equivalents" (although not listed as such in the "International Classification of Headache Disorders"), which can be good predictors of the future development of typical migraines. Individuals who experience acephalgic migraines in childhood are highly likely to develop typical migraines as they grow older. Among women, incidents of acephalgic migraine increase during perimenopause.

Scintillating scotoma is the most common symptom which usually happens concurrently with Expanding Fortification Spectra. Also frequently reported is monocular blindness. Acephalgic migraines typically do not persist more than a few hours and may last for as little as 15 seconds. On rare occasions, they may continue for up to two days.

Acephalgic migraines may resemble transient ischemic attacks or, when longer in duration, stroke. The concurrence of other symptoms such as photophobia and nausea can help in determining the proper diagnosis. Occasionally, patients with acephalgic migraine are misdiagnosed as suffering epilepsy with visual seizures, but the reverse misdiagnosis is more common.

The medical exam should rule out any underlying causes, such as blood clot, stroke, pituitary tumor, or detached retina. A normal retina exam is consistent with retinal migraine.

MOH is common and can be treated. The overused medications must be stopped for the patient's headache to resolve. Clinical data shows that the treatment of election is abrupt drugs withdrawal, followed by starting prophylactic therapy. However, the discontinuation of overused drugs usually leads to the worsening of headache and the appearance of drug withdrawal symptoms (that greatly depend on the previously overused drugs and typically last from two to ten days and that are relieved by the further intake of the overused medication), which might reinforce the continuation of overuse. Where physical dependence or a rebound effect such as rebound headache is possible, gradual reduction of medication may be necessary. It is important that the patient's physician be consulted before abruptly discontinuing certain medications as such a course of action has the potential to induce medically significant physical withdrawal symptoms. Abruptly discontinuing butalbital, for example, can actually induce seizures in some patients, although simple over the counter analgesics can safely be stopped by the patient without medical supervision. A long-acting analgesic/anti-inflammatory, such as naproxen (500 mg twice a day), can be used to ease headache during the withdrawal period. Two months after the completion of a medication withdrawal, patients suffering from MOH typically notice a marked reduction in headache frequency and intensity.

Drug withdrawal is performed very differently within and across countries. Most physicians prefer inpatients programmes, however effective drug withdrawal may also be achieved in an outpatient setting in uncomplicated MOH patients (i.e. subjects without important co-morbidities, not overusing opioids or ergotaminics and who are at their first detoxification attempt). In the absence of evidence-based indications, in MOH patients the choice of preventive agent should be based on the primary headache type (migraine or TTH), on the drug side-effect profile, on the presence of co-morbid and co-existent conditions, on patient’s preferences, and on previous therapeutic experiences.

Following an initial improvement of headache with the return to an episodic pattern, a relevant proportion (up to 45%) of patients relapse, reverting to the overuse of symptomatic drugs.

Predictors of the relapse, and that could influence treatment strategies, are considered the type of primary headache, from which MOH has evolved, and the type of drug abused (analgesics, and mostly combination of analgesics, but also drugs containing barbiturates or tranquillisers cause significantly higher relapse rates), while gender, age, duration of disease and previous intake of preventative treatment do not seem to predict relapse rate.

MOH is clearly a cause of disability and, if not adequately treated, it represents a condition of risk of possible co-morbidities associated to the excessive intake of drugs that are not devoid of side-effect. MOH can be treated through withdrawal of the overused drug(s) and by means of specific approaches that focus on the development of a close doctor-patient relationship in the post-withdrawal period.

In general, any patient who has frequent headaches or migraine attacks should be considered as a potential candidate for preventive medications instead of being encouraged to take more and more painkillers or other rebound-causing medications. Preventive medications are taken on a daily basis. Some patients may require preventive medications for many years; others may require them for only a relatively short period of time such as six months. Effective preventive medications have been found to come from many classes of medications including neuronal stabilizing agents (aka anticonvulsants), antidepressants, antihypertensives, and antihistamines. Some effective preventive medications include Elavil (amitriptyline), Depakote (valproate), Topamax (topiramate), and Inderal (propranolol).

Scintillating scotomas are most commonly caused by cortical spreading depression, a pattern of changes in the behavior of nerves in the brain during a migraine. Migraines, in turn, may be caused by genetic influences and hormones. People with migraines often self-report triggers for migraines involving stress and a wide variety of foods. While monosodium glutamate (MSG) is frequently reported as a dietary trigger, some scientific studies do not support this claim.

The Framingham Heart Study, published in 1998, surveyed 5,070 people between ages 30–62 and found that scintillating scotomas without other symptoms occurred in 1.23% of the group. The study did not find a link between late-life onset scintillating scotoma and stroke.

An aura sensation can include some or a combination of the following:

Because epileptic seizures may occur with a side effect that resembles migraine aura, it is complicated to diagnose whether a patient is having a normal epileptic episode or if it is a true migraine that is then being followed by a seizure, which would be a true sign of migralepsy. Many neurological symptoms can only be expressed by the patient, who can confuse different feelings, especially when the symptoms of a migraine are extremely similar to that of a seizure. Thus, many physicians are reluctant to consider migralepsy to be a true condition, considering its rarity, and those that do believe in it are prone to over-diagnose it, leading to more problems in terms of finding the truth of the condition.

However, it has been found that EEG scans have been able to differentiate between migraine auras and auras related to epilepsy. It has generally been seen that EEG scans are not as helpful in determining facets of migraines as they are with epilepsy. Though they are able to work in determining the starting and ending points of migraines and the overlap of epileptic episodes during or after them, even if the scans are still lacking in considerable necessary data and confusing results. EEG scans have been able to observe seizures that occur in between the aura and headache phase of migraines and such occurrences have been termed intercalated seizures.

Symptoms typically appear gradually over 5 to 20 minutes and generally last fewer than 60 minutes, leading to the headache in classic migraine with aura, or resolving without consequence in acephalgic migraine. Many migraine sufferers change from scintillating scotoma as a prodrome to migraine to scintillating scotoma without migraine. The scotoma typically spontaneously resolves within the stated time frame, leaving few or no subsequent symptoms, though some report fatigue, nausea, and dizziness as sequelae.

A vascular headache is an outdated term to describe certain types of headache which were thought to be related to blood vessel swelling and hyperemia as cause of pain.

There is no doubt that "some" headaches are caused by vascular effects. However, it is no longer a recognized term and not mentioned in the Headache classification of the International Headache society (IHS), although it is still used by some physicians and still mentioned in some medical classification systems. There are many types of vascular headaches. Other types of vascular headaches include headaches produced by fever, cluster headaches, and headaches from a rise in blood pressure (OSU Wexner Medical Center, 2012).

Headaches that were described as being vascular headaches include:

- Cluster headache

- Migraine

- Toxic headache