Headaches often strike when you least expect them--and they can range in severity from dull throbs and intense aches to debilitating pain. In fact, they land someone in the emergency room every 10 seconds, according to the American Headache Society. As if that weren't frustrating enough, oftentimes the direct cause of a headache is unknown. The good news is that by learning more about headaches, you may be able to pinpoint their source, manage your symptoms more effectively, and even prevent them. Here, the four most common types of headaches.

Tension Headaches:

Also known as stress headaches, tension headaches are the most common type of headache and are often described as tight bands of pressure around the head that can last from 30 minutes to an entire week. They are frequently accompanied by sound and light sensitivity, throbbing temples, sleep disruption, disturbed concentration, and even nausea and vomiting. Although there is no single cause for tension headaches, they can often be attributed to stress, fatigue, depression, and psychological or physical problems, according to the National Headache Foundation (NHF).

Treatment for tension headaches is typically aspirin, ibuprofen, or other nonprescription pain relievers. Prescription medications are rarely needed, but may be helpful in extreme cases if over-the-counter products prove ineffective, according to the American Academy of Family Physicians (AAFP). Because triggers range from stress and depression to lack of sleep and weight gain, stress management techniques and a diet and exercise program may also go a long way toward minimizing the frequency and intensity of your headaches--and in some cases, can even prevent them entirely.

Migraines:

Recurrent and frequently disabling, migraines typically start in a specific area on one side of the head, then spread and increase in intensity before gradually subsiding. They can last from a few hours to several days and may be accompanied by nausea, vomiting, depression, sleep disruption, and sensitivity to sound, light, and smells. In some cases, the pain can be so severe that it interferes with daily activities and work.

According to the World Health Organization, migraines occur when a mechanism deep in the brain is activated, causing pain-producing inflammatory substances to be released around the nerves and blood vessels of the head. The exact causes are still unknown, but researchers have identified a strong genetic component. Up to 75 percent of migraine sufferers are women, and "menstrual migraines" caused by hormonal changes are quite common.

Treatment of migraines falls into two categories: abortive and preventative. Abortive pain-relieving medications, designed to stop symptoms of an attack once it has already started, include ibuprofen or aspirin (for mild migraines), as well as triptans or ergots, which are designed to relieve the nausea and light and sound sensitivity that are specific to migraines. Preventative medications can reduce the frequency and severity of migraine attacks, while also helping to increase the effectiveness of the abortive medications, once an attack has occurred. These drugs include antidepressants, beta-blockers (often used to treat high blood pressure), and even anti-seizure medications.

Cluster Headaches:

Most frequently experienced by men, cluster headaches are the rarest type of headache but one of the most painful. This type of headache is known for occurring in groups, or "clusters," and the nature of the pain is distinctive; it comes on very suddenly and tends to be extremely sharp around the eyes. Red or teary eyes and facial swelling are also common signs. An individual who suffers from this type of headache may experience several attacks daily for weeks or months, separated by headache-free periods of varying duration. These patterns are important for making a diagnosis and should be recorded in a diary if this type of condition is suspected, according to the AAFP.

Although the exact cause is unclear, many experts theorize that cluster headaches may be related to a disturbance of serotonin (a neurotransmitter that can affect mood) levels in the brain. Unlike with migraines, there does not appear to be a genetic component to this condition. Alcohol, heavy smoking, ingestion of certain foods, and stress are common triggers and should be minimized or avoided if possible.

Because of the nature cluster headaches (they come on suddenly and often subside quickly), over-the-counter medications such as aspirin or ibuprofen are usually ineffective, since by the time they start working, the episode may have passed. For this reason, preventative medications such as lithium, anti-seizure medications, and steroids that are taken on a regular basis are often prescribed, according to the NHF.

Sinus Headaches:

Characterized by congestion, a throbbing head, and pressure around the cheeks, eyes, and forehead, the signs of a sinus headache often overlap with those of a migraine--making monitoring your symptoms for accurate diagnosis essential. When your sinuses (which are located behind your forehead and cheekbones) become inflamed from an infection or allergic reaction, the result is a localized and often severe pain that may be paired with a sore throat, runny nose, and postnasal drip. The longer a sinus infection goes unchecked, the more clogged the sinuses will become, thus worsening the pain.

The most common causes of sinus headaches are respiratory infections and allergies, but they can sometimes result from changes in atmospheric pressure or swimming. Certain factors, such as having a history of allergies or asthma or an abnormal structure of your sinus area (such as a deviated septum), can aggravate or increase the frequency of attacks. Prescription antibiotics are often necessary if a bacterial infection is suspected, while over-the-counter decongestants and nasal sprays are frequently used for sinus headaches that result from allergies or asthma. In cases that become unmanageable, surgery may also be an option, according to the American Academy of Otolaryngology Head and Neck Surgery.