Headache is a pain which can happen in any region of your head. Headaches can happen on one side of the head or on the both sides. It can be isolated to a certain location. It can radiate across the head from one point or it can have a viselike quality. Headache can appear as a dull ache, a throbbing sensation or a sharp pain. Headaches can develop suddenly or gradually. They can last from less than an hour or they can last for several days.
Causes of Headache
You should tell your doctor about your headache symptoms. He or she will determine the cause for it and he or she will give you an appropriate treatment. In the most cases headaches are not a result of serious disease. But also there are some types of headaches which can be a result from life – threatening conditions and they are requiring emergency care. Headaches are generally classified by the cause.
Symptoms of headaches
There are two types of headaches – primary and secondary.
- Primary headaches: This type of headache is caused by problems with pain – sensitive structures in your head or by over activity with these pain – sensitive structures. When you have a primary headache, then you should know that it is not a symptom of some underlying disease. There are some factors which can play a role in primary headaches such as the muscles of your head and neck, the nerves or blood vessels surrounding your skull, chemical activity in your brain or some combination of the mentioned factors. Also there are some people who can have genes that will make them more likely to develop the primary headaches.  The most common primary headaches are:
- Trigeminal autonomic cephalalgia (TAC), such as paroxysmal hemicranias and cluster headache
- Tension headache – which is also known as tension – type headache
- Migraine – with and without aura
- Cluster headache
A few headache patterns are also generally considered as types of primary headache but they are not so common. These headaches have distinct features such as pain associated with a certain activity or unusual duration associated with some type of activity. Although considered as primary type of headache, each could be a symptom of underlying disease and they include:
- Sex headaches
- Exercise headaches
- Cough headaches
- Chronic daily headaches – for example hemicranias continua, chronic tension – type headache and chronic migraine
Also there are some primary headaches which can be triggered by some lifestyle factors and they are including:
- Stress 
- Skipped meals
- Poor posture
- Changes in sleep or lack of sleep 
- Certain foods such as processed meats that contain nitrates
- Alcohol, particularly red wine 
- Secondary headaches: A secondary headache is a symptom of a disease which can activate the pain – sensitive nerves of your head. Any number of conditions, which can vary greatly in severity, can cause secondary headaches.  Here are the possible causes of secondary headaches:
- Trigeminal neuralgia, as well as other neuralgias, all involving irritation of certain nerves connecting the face and brain
- Stroke 
- Pseudotumor cerebi, this is an increased pressure inside the skull, which is also known as idiopathic intracranial hypertension
- Pressure from tight headgear, such as a helmet or goggles
- Post – concussion syndrome
- Overuse of pain medication 
- Monosodium glutamine (MSG) 
- Meningitis – inflammation of the membranes and fluid surrounding your brain and spinal cord
- Medications to treat other disorders
- Intracranial hematoma (blood vessel ruptures with bleeding in or around the brain)
- Influenza (flu) and other febrile (fever) illnesses
- High blood pressure (a condition which is known as hypertension) 
- Glaucoma (acute angle closure glaucoma)
- Giant cell arthritis (inflammation of the lining of the arteries)
- Encephalitis (brain inflammation)
- Ear infection (infection which is happening in the middle ear)
- Dental problems
- Chiari malformation (structural problem at the base of your skull)
- Carbon monoxide poisoning
- Brain tumor 
- Brain AVM (brain arteriovenous malformation)-an abnormal formation of brain blood vessels
- Brain aneurysm (a bulge in artery in your brain)
- Blood clot (venous thrombosis) within your brain – separate from stroke
- Arterial tears (carotid or vertebral dissections)
- Acute sinusitis
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