Each one of us suffers from headache at some time or the other. If it occurs often, you should pay attention to the symptoms so that you can provide accurate and sufficient information to your doctor. This helps detect the cause of the pain. There can be several causes, and there are several types of pain as well. Eye problems, acidity, indigestion, insufficient sleep, food poisoning, sinusitis, physical or emotional stress are some of the most common causes of sharp headache. Vital Information Sharp pain on the backside of the head is the pain that begins in the upper neck as a band-like tightness or pressure. Migraine can lead to severe pain on one side. Despite the pain, most people are able to finish their routine work. But if the pain is sharp and recurring, it should not be left untreated, as it can be one of the symptoms of serious underlying diseases. Some people may suffer from severe aches frequently or even daily. The type, severity and duration of the pain, the associated symptoms, like nausea or vomiting, help determine the reason behind the pain. Over-the-counter pain relievers work great and can be taken once in a while. But to determine the exact cause, a proper physical examination is necessary. The doctor might order tests, like CT scan, MRI, blood test, etc. to find out the cause. Causes

• Constipation: Constipation is a very common cause. Though it appears as a simple reason, it can result in digestive system dysfunction due to some severe problems like tumors, adhesion, cancers, etc.
• Sinusitis: Sinus headaches are also very common. Sinusitis gives rise to sharp pain in head behind eyes or behind ear. Constant pain when bending over, is a common symptom of sinusitis.
• Brain Tumor: Brain tumors, brain injuries, or brain cancer can lead to a stabbing pain in the head. Therefore, it is necessary to consult the physician and undergo various examinations to determine the exact cause. The earlier the diagnosis, greater are the chances of fast recovery.
• Meningitis: Meningitis is the condition wherein inflammation of the meninges, i.e., tissues surrounding brain and the spinal cord occurs due to bacterial or viral infection. This is a very serious condition. Stiff neck, nausea, vomiting, sensitivity to light, seizures, unconsciousness, loss of appetite, sharp pain in entire head are some of the most common symptoms of meningitis.
• Allergies: Allergies can lead to mild or severe ache. If you are allergic to any kind of food, chemical, pollens, etc., then it is better to stay away from such allergens. You should avoid eating the food, which contains allergens. You should cover your nose, eyes, ears, and head well, to keep yourself away from the allergens whenever or wherever there is possibility of facing them.
• Encephalitis: Encephalitis is caused by enteroviruses or other bacteria and viruses that enter your body through insect bites, food or drink, or skin contact. Viral or bacterial infection causes encephalitis, which is one of the most prominent causes of pain in the head, leading to the inflammation of the brain. There are innumerable parasites that can cause encephalitis. Sharp headache, nausea, vomiting, seizures, confusion, convulsions, and fever are the other encephalitis symptoms.
• Other Causes: Change in sleep patterns, excessive smoking, alcohol abuse, drugs consumption, consumption of specific foods, excessive use of pain killers or some other medicines, irregular and unhealthy diet leading to vitamins or nutrients deficiency, extreme weather conditions like too hot or too cold weather, eye problems, outset of puberty, premenstrual syndrome, high blood pressure, hypothyroidism, dehydration, renal failure, problems with the ear, nose, teeth, and neck, flu, pneumonia, HIV/AIDS, etc., can lead to piercing headache.

People who experience this tend to be restless. Some people often pace the floor, or some even bang their heads against a wall. Prompt medical attention is required if the pain experienced is different from the usual one, and is associated with persistent nausea, vomiting, fever, stiff neck, seizures, head trauma or a fall, change in sensation, weakness or changes in vision, speech or behavior. If the pain does not subside with one dose of over-the-counter medicine, and if it is interfering with work and quality of life, then you should immediately consult your physician. Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a replacement for expert medical advice.