Pain originating in the face might radiate to the head, leading to headache. Facial pain related headaches might be caused by an abscessed tooth, injury to the face, inflammation or infection of the sinuses or a disorder in the jaw joint.

Severe headache accompanied by a stiff neck and fever might indicate meningitis. The brain is covered by a protective membrane called meninges. Meningitis occurs when the meninges is swollen. It is primarily caused by viral, bacterial, parasitic or fungal infections. The disease can also be triggered by physical injury, certain medications and cancer. The swelling of the meninges increases the intracranial pressure inside the brain, stimulating the debilitating headache.

A brain tumor can cause headaches. A headache occurs when a tumor damages a specific area of the brain, presses a nerve or fluid builds up in the skull, leading to swelling of certain areas of the brain. In people with brain tumor, the headache is especially severe in the morning. However, headaches are not always the initial symptom of brain tumor. It may be preceded by weakness in hands and legs, vision changes, cognitive problems, nausea or seizures. Headaches might develop at a later stage of the illness, when the intracranial pressure in the brain rises. With further growth of the tumor, the headache becomes more frequent and severe.

Brain hemorrhage is the most dire cause of headaches. A sudden severe headache can be a symptom of blood leaking from a cerebral aneurysm. If an area in the wall of an artery in the brain is weakened, it may bulge out, forming a cerebral aneurysm. Atherosclerosis is the most common cause of cerebral aneurysm. Infections and trauma can also weaken the wall of a blood vessel in the brain. Hemorrhagic stroke occurs when the aneurysm ruptures. The blood leaking from the cerebral aneurysm collects underneath the membranes that cover the brain (meninges), causing severe headache.

Abnormal activities in the hypothalamus cause cluster headaches. In most cases, genetics play a role in inducing cluster headaches. Poor sleep, certain medications, especially nitroglycerin, exposure to tobacco smoke, alcohol and certain food items trigger this rare form of headache. It is estimated that about one in every 1,000 people, especially men in their late 20s, experience cluster headaches.

Migraine attacks are the second most common cause of headaches. It is estimated that about 18 percent adult women and 6 percent adult men are troubled by migraine headaches. These occur when the blood vessels are dilated. The enlarged arteries in the brain exert pressure on the surrounding nerves, leading to excess secretion of chemicals that trigger pain, inflammation and increase the dilation of the arteries. The headache worsens with further enlargement of the arteries. The cause of migraine headache varies from person to person. It can be triggered by various physiological and environmental factors such as stress, hormonal changes during menstrual cycle, sleep deprivation, fasting, bright light, loud sound and certain ingredients in foods such as caffeine, tyramine, nitrites, nitrates, aspartame and monosodium glutamate.

Almost 90 percent adults experience tension headaches several times in their lives. It occurs when the muscles surrounding the skull get constricted owing to physical or mental stress. Spasms induced by the stressed muscles causes the throbbing headache. The forehead, temple, and the base of the skull are the common sites of tension headache. The muscles in the neck and scalp become tensed when the head is held in the same position without any movement for a prolonged period, such as while sitting in front of the computer or sleeping with the neck placed in an abnormal position. The muscles might be stressed also by cold and flu, fatigue, eyestrain, clenching the jaws, grinding the teeth, excess smoking, too much caffeine or alcohol consumption, manual labor and anxiety.