Almost everyone has had a headache. Whether they occur on the back of our heads or across the forehead, we know what they are. We ascribe the cause to allergies, stress, a cold, or even migraines, often without ever seeking any medical opinion. A couple of Tylenol or a nap usually does the trick and we don't think of it again. Headaches, however, have many causes and are poorly understood, even by the medical community.

Headaches are grouped into two types. Primary headaches are headaches that are the primary condition. There is no known underlying cause or symptoms separate from the headache itself. The main disorders in this group are migraines, tension type headaches and cluster headaches. There are also other miscellaneous headaches that fall into this category, as no apparent cause can be found for the headache to occur. These include headaches that are brought on by the cold or by coughing. External compression headaches can be triggered by applying pressure to parts of the head, such as tying on a headband.

Secondary headaches are headaches that are caused by a known condition. That condition is the primary concern and the headache is just a symptom. The primary condition may be structural, as in TMJ, or temporomandibular joint, syndrome. The TMJ causes the headache. Once the primary condition is addressed, the headache resolves, along with any other symptoms. If you have a sinus infection, you know that the headache will go away once the infection is cleared up. If you have a hangover, you know that the headache is secondary to the dehydration you are suffering - and a reminder to be more careful next time.

Sometimes headaches that are thought to be primary are, in fact, secondary. This happens when recurring headaches are the initial complaint to a physician and they seem to be migraine-like in behavior and do not appear to have any underlying physical cause. However, it is very important to distinguish between causes and triggers (things that aid the onset of the headache) when dealing with an initial diagnosis of migraine. Your doctor should ask you to keep a journal of what you are eating to help you determine things that potentially trigger your migraine attacks. What may seem like a trigger may, in fact, be the cause. Food allergies and lactose intolerance fall into this category. If avoiding those items stops the headaches from ever occurring again, your headaches are a secondary condition. If avoiding those items only reduces the amount of attacks, the items are true dietary triggers.

Headaches can also serve as a warning to a more serious, underlying condition. Do not diagnose yourself. If you have no family history of migraines, you could be wrong. Make an appointment with a physician to get properly diagnosed. There are some headache symptoms that call for immediate attention, whether to an emergency room or your doctor's office. One of these would be a stiff neck and/or fever associated with the headache, as you may be suffering from a viral infection like meningitis. If the headache follows any sort of head injury, bleeding in the brain may be occurring and must be ruled out with a cat scan. If you have any neurological symptoms with the headache, like numbness, tingling, and/or paralysis, you could have had a stroke. Headaches that last longer than 72 hours or a headache that is the worst headache of your life can indicate tumors, bleeding in the brain, an aneurism (a weakened blood vessel), or even carbon monoxide poisoning. Play it safe with headaches and seek medical attention whenever any of these conditions apply.