Headache is the symptom of pain anywhere in the region of the head or neck. It occurs in migraines (sharp, or throbbing pains), tension-type headaches, and cluster headaches. Frequent headaches can affect relationships and employment.There is also an increased risk of depression in those with severe headaches.Headaches can occur as a result of many conditions whether serious or not. There are a number of different classification systems for headaches. The most well-recognized is that of the International Headache Society. Causes of headaches may include dehydration, fatigue, sleep deprivation, stress, the effects of medications, the effects of recreational drugs, viral infections, loud noises, common colds, head injury, rapid ingestion of a very cold food or beverage, and dental or sinus issues.Treatment of a headache depends on the underlying cause, but commonly involves pain medication. A headache is one of the most commonly experienced of all physical discomforts.About half of adults have a headache in a given year.Tension headaches are the most common, affecting about 1.6 billion people (21.8% of the population) followed by migraine headaches which affect about 848 million (11.7%).Encyclopedia Entry for Headaches :Headaches - danger signs. Problems with blood vessels and bleeding in the brain can cause a headache. These problems include: Abnormal connection between the arteries and veins in the brain that usually forms before birth. This problem is called an arteriovenous malformation , or AVM. Blood flow to part of the brain stops. This is called a stroke. Weakening of the wall of a blood vessel that can break open and bleed into the brain. This is known as a brain aneurysm. Bleeding in the brain. This is called an intracerebral hematoma. Bleeding around the brain. This can be a subarachnoid hemorrhage , a subdural hematoma , or an epidural hematoma. Other causes of headaches that should be checked by a health care provider right away include: Acute hydrocephalus , which results from an interruption of cerebrospinal fluid flow. Blood pressure that is very high. Brain tumor. Brain swelling (brain edema) from altitude sickness, carbon monoxide poisoning, or acute brain injury. Buildup of pressure inside the skull that appears to be, but is not, a tumor ( pseudotumor cerebri ). Infection in the brain or the tissue that surrounds the brain , as well as a brain abscess. Swollen, inflamed artery that supplies blood to part of the head, temple, and neck area ( temporal arteritis ).If you cannot see your provider right away, go to the emergency room or call 911 if: This is the first severe headache you have ever had in your life and it interferes with your daily activities. You develop a headache right after activities such as weightlifting, aerobics, jogging, or sex. Your headache comes on suddenly and is explosive or violent. Your headache is 'the worst ever,' even if you regularly get headaches. You also have slurred speech, a change in vision, problems moving your arms or legs, loss of balance, confusion, or memory loss with your headache. Your headache gets worse over 24 hours. You also have fever, stiff neck, nausea, and vomiting with your headache. Your headache occurs with a head injury. Your headache is severe and just in one eye, with redness in that eye. You just started getting headaches, especially if your are older than 50. You have headaches along with vision problems and pain while chewing, or weight loss. You have a history of cancer and develop a new headache. Your immune system is weakened by disease (such as HIV infection) or by medicines (such as chemotherapy drugs and steroids). See your provider soon if: Your headaches wake you up from sleep. A headache lasts more than a few days. Headaches are worse in the morning. You have a history of headaches but they have changed in pattern or intensity. You have headaches often and there is no known cause.Migraine headache - danger signs; Tension headache - danger signs; Cluster headache - danger signs; Vascular headache - danger signs.Headache Headache Tension-type headache Tension-type headache CT scan of the brain CT scan of the brain Migraine headache Migraine headache.Digre KB. Headaches and other head pain.