Causes of Headache | Find out why you often get Headache

Primary Headache

1. Tension-Type Headache (TTH)

Tension headache, also known as a tension-type headache (TTH), is the most common type of primary headache. It is also the most common headache in the general population, and the second-most prevalent disorder in the world 

The mean global prevalence of TTH in adult is 42%. Due to its high prevalence in the population, TTH causes a high degree of disability.

Surprisingly little research on the disorder has actually been carried out and knowledge about the underlying causes and mechanisms is therefore limited. This may partly be due to the lack of a proper classification. Before 1988, no precise definition of tension-type headache was available, and several terms such as muscle contraction headache, tension headache, psychogenic headache, psychomyogenic headache, or stress headache were used 

The headache in TTH is rarely severe. It is often band-like and aching and usually not throbbing. It usually affects both sides of the head and is not associated with light and sound sensitivity or nausea and vomiting. Muscle tenderness in the head, neck, or shoulders is often present.

Tricyclic antidepressants, including amitriptyline and protriptyline, are the most commonly used medications to prevent TTH.

2. Migraine

Migraine is a disorder of recurrent attacks of headache. It is often described as severe throbbing pain or a pulsing sensation, usually on one side of the head. It is commonly accompanied by nausea, vomiting, and sensitivity to light and sound.

Prodromal symptoms may occur one or two days before the attack . These include constipation or diarrhea, mood changes, appetite changes including food cravings, concentration difficulties, cold extremities, increased thirst, frequent urination and constant yawning.

Warning symptoms known as aura may occur before or together with the headache. These include visual disturbances and sensory abnormalities such as a tingling or touching sensation on one side of the face or in an arm or a leg . However, most patients (75-80%) with a migraine don’t experience an aura.

There are some known trigger factors for migraine attacks such as emotional stress, menstruation, visual stimuli such as bright lights, fasting, wine, physical exertion, sleep disturbances, intake of highly caffeinated beverages and aspartame, among others.

3. Cluster Headache

Cluster headache, also known as histamine headache, is a rare disorder that affects about 1-2 people in every 1.000.

It is characterized by a severe pain in one side of the head, often the eye, temple or forehead. The pain may begin quickly and without warning. It may be very intense but does usually not last for more than 1-2 hours.

At least one of the following associated symptoms is usually present:

• a red and watering eye
• drooping and swelling of one eyelid
• a smaller pupil in one eye
• a sweaty face
• a blocked or runny nostril

People who smoke seem to have a higher risk of getting cluster headaches. Some cases also appear to run in families. Cluster headache attacks can sometimes be triggered by drinking alcohol or by strong smells, such as perfume, paint or petrol.

Secondary Headache

4. Upper Respiratory Tract Infections

Upper respiratory tract infections are a common cause of headache. In children and adolescents presenting to the ED, upper respiratory tract infections are the most frequent underlying cause of acute headache (57%). These are further divided into viral upper respiratory tract infection 39%, sinusitis 9%, and streptococcal pharyngitis 9%. There is often associated fever and a sore throat.

A sinus headache is commonly diagnosed by physicians and self-diagnosed by patients. However, sinusitis appears to be an uncommon cause of recurrent headaches, and many patients presenting with sinus headache turn out to have migraine.

5. Encephalitis and Meningitis

Encephalitis is an infection of the brain most often caused by a viral infection. It is characterized by fever, seizures, change in behavior, confusion, and disorientation

Meningitis is an inflammatory process of the membranes that surround the brain.  When caused by bacteria it is called bacterial meningitis. These bacteria usually infect the mucosa of the upper airways from where they may enter the bloodstream and ultimately cross the blood-brain barrier and enter the brain.

The most common types of bacterial meningitis include pneumococcal meningitis and meningococcal meningitis. Some 6,000 cases of pneumococcal meningitis are reported in the United States each year.

Bacterial meningitis is a rare but potentially fatal disease. Haemophilus meningitis used to be the most common form of bacterial meningitis. The Haemophilus influenza b vaccine has significantly reduced the number of cases in the United States.

7. Stroke

A stroke occurs when the blood flow to the brain is interrupted. If blood doesn’t reach the brain, brain cells will die, and permanent brain damage can occur.

In ischemic stroke, a blood clot blocks the flow of blood to areas of the brain. In hemorrhagic stroke, there is bleeding into brain tissue, most commonly because of a burst vessel.

A patient in the early phases of a stroke may experience a headache. The headache may be accompanied by dizziness or vomiting. However, most patients will have neurologic deficits as well, such as an inability to move a limb, sensory deficits, slurred speech or an inability to speak.

8. Head Trauma

A headache immediately following a head injury usually disappears after minutes or days. However, sometimes headaches may persist for months or years after the injury. These long-term headaches are called post-traumatic or post-concussion headaches.

Post-traumatic headaches typically affect both sides of the head and often occur daily.  They are of slight to moderate intensity. However, bouts of more severe headache may occur and these may be similar to migraine with one sided throbbing pain associated with nausea and sensitivity to light and noise.

9. Chronic Subdural Hematoma  (SDH)

A chronic subdural hematoma (SDH) is an old clot of blood on the surface of the brain beneath its outer covering. The most common complaint is headache, seen in up to 80 percent of patients.

SDH is most common in patients age 60 and older. Many patients have an underlying brain atrophy, a shrinking of brain tissue, usually due to age or disease.

SDH is usually precipitated by a minor head trauma which cause tearing of blood vessels over the brain surface, resulting in a slow accumulation of blood over several days to weeks. The trauma may be trivial and is often not remembered by the patient himself.

10. Brain Tumor

Headache is one of the most common symptoms experienced by patients with brain tumors. The headache is usually steady but often worse in the morning. It is generally much more persistent than migraine headache. It is sometimes associated with nausea or vomiting. It may worsen with coughing, exercise, or a change in body position and does not usually respond to the usual headache remedies.

The signs and symptoms of a brain tumor vary greatly and depend on the brain tumor’s size, location, and rate of growth.

Tumors in the back part of the brain (posterior fossa) may be accompanied by dizziness or unsteady gait.

Tumors in the principal part of the brain  (cerebrum) may cause speech difficulties or gradual loss of sensation or movement in an arm or a leg.