A headache, which is medically referred to as cephalalgia, is defined as a pain in any part of the head. It occurs when the nociceptors in the head, which are sensory neurons that respond to pain, get stimulated. While the brain itself doesn't contain nociceptors, the cranial and spinal nerves, extracranial arteries, meninges, and muscles in the head and neck region contain pain receptors. These pain receptors may get stimulated due to muscular tension, stress, or dilated blood vessels. Pain is felt when the receptors send message to the nerve cells in the brain. Pain which is felt during a headache could be generalized or localized to the side, front or the back of the head. It could be dull or sharp. It could be intermittent or constant. At times, the affected individual may experience a pulsating or throbbing sensation. Sometimes, pain may be of a debilitating nature, and the affected individual may find it extremely hard to indulge in any activity. What Causes Pain at the Base of the Skull? Headaches are classified into primary and secondary headaches. In case of a primary headache, pain in the head is not caused by an underlying condition. When a medical condition is responsible for causing a headache, it is referred to as a secondary headache. Tension Headaches Tension headaches occur when the muscles located in the neck, or the head tighten. It is believed that these headaches occur due to stress. Fluctuations in the levels of neurotransmitters could be a contributory factor for such headaches. More often than not, pain is first felt at the back of the head. The affected individual is likely to experience a dull, squeezing pain or a sensation of tightness in the head. Sleep deprivation, teeth grinding, stress, anxiety, fatigue, and poor posture are some of the contributory factors for muscular tension. Vascular Headaches Migraine refers to a recurring and severe vascular headache that may be accompanied by nausea, vomiting, and increased sensitivity of light and sound. Migraine commonly affects women. During an episode, the affected individual is likely to experience a throbbing or pulsating sensation on one side of the head. At times, pain may be felt in the back of the head and neck. It is believed that sleep deprivation, stress, anxiety, and fatigue could act as triggers. Cervicogenic Headaches A cervicogenic headache is a secondary headache that is caused by neck problems. It is classified into myogenic and vertebrogenic headaches. Myogenic headaches occur when the neck muscles get strained. Poor posture, stress, or abnormalities in the cervical spine could be contributory factors. Vertebrogenic headaches occur when the spinal joints in the neck are irritated or dysfunctional. The spinal cord is connected to the skull at the craniocervical junction. Craniocervical junction abnormalities could also cause occipital and suboccipital headaches (pain that originates from the base of the skull). The pain may radiate towards the shoulders and back. The pain may originate in the neck and spread to the back, side and top of the head. Sinus Headaches Sinuses are four pairs of air-filled spaces that lie within the skull. The mucous membranes that line these cavities secrete mucus, thereby moistening the nasal passages. Infection or inflammation of sinuses can cause headaches. Inflammation of sphenoid sinuses that lie deep within the skull can give rise to pain in back of the head. The pain tends to increase when the affected individual bends forward. Occipital Neuralgia The term 'occiput' refers to the base of the skull. Occipital neuralgia refers to a medical condition that occurs when the occipital nerves, which are a pair of nerves that originate from the second and third vertebrae of the spinal column, get damaged. The top and the back of the head is supplied by these nerves. If these nerves get damaged or inflamed due to an injury to the neck, infections, tumors, osteoarthritis of the neck or spinal column compression, the affected individual is most likely to experience pain in back of the head. The affected individual should take rest. The use of steroids, nerve block injections or painkillers may be recommended. Massage therapy would also prove beneficial. Temporal Arteritis Temporal arteritis refers to the inflammation of the large and medium arteries that supply the head. The exact cause of this condition is not known, but it is believed that it may develop due to an immune response. People who suffer from severe infections or those who have been taking large doses of antibiotics are believed to be at a greater risk of developing this condition. Vision problems, tenderness of the scalp, pain in one side or back of the head, muscle aches, jaw pain, etc., are some of the symptoms of temporal arteritis. Since this is an inflammatory condition, the treatment involves the use of corticosteroids. If you suffer from severe headaches every now and then, do consult a physician or neurologist immediately. In rare cases, headaches could occur due to serious medical conditions such as brain tumor, stroke, meningitis or encephalitis (acute inflammation of the brain). This is the reason why doctors often conduct diagnostic tests and imaging studies to ascertain the underlying cause of such headaches. The treatment would vary, depending on the underlying cause. If pain in back of the head is due to sleep deprivation, eye strain, or stress, making lifestyle changes can considerably reduce the frequency of such headaches. Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a replacement for expert medical advice.