Who hasn't had a nagging headache that just wouldn't quit? But headaches aren't all the same. In fact, there are particular characteristics to each type of headache — and definite ways each type differs from the rest. Before you take your next ibuprofen, read what the experts have to say. We're sure this headache primer will help make you feel empowered the next time your head is aching.

What is a cluster headache?

Symptoms: Sharp and intense stabbing pain usually on one side of the head. "These can appear on one side of the head behind the eye or in the temple region," says Dr. Chad Hoyle, assistant professor of neurology at Ohio State University in Columbus. "These are very severe in intensity."

What to watch for: You may also have related symptoms on that side of your head. "You may experience tearing of that eye, a runny nose out of that nostril or even a droopy eye or pupil change," Hoyle adds.

What to do: While there is no "cure" for cluster headaches, two ways to prevent one include maintaining good sleep habits (including sticking to the schedule that works for you) and avoiding alcohol since drinking has been shown to trigger a cluster headache.

What is a migraine?

Symptoms: Pounding, throbbing, pulsating pain paired with light or sound sensitivity that can be one side of the head or both.

What to watch for: A migraine may also come with nausea or vomiting. "You may also see auras or sparkly unusual visual patters before the migraine comes on," says Hoyle. "You may also get a tinging sensation in your head."

What to do: Lay down in a dark room as quickly as you can. Consider two homeopathic medications: Vitamin B2 (riboflavin) or magnesium, says Dr. Seth Stoller, a neurologist and medical director of the Headache Center at Overlook Medical Center in Summit, New Jersey. If you experience routine migraines, Stoller recommends supplementing with 400 mg daily of riboflavin (main side effect: urine discoloration) and 400-500 mg daily of magnesium (main side effect: stomach discomfort or diarrhea, though this is rare). Prescription medications such as Imitrex work on the part of the brain that involves spasms of the blood vessels but Ausanil, a nasal spray derived from capsaicin, can also be helpful at easing symptoms.

What is a sinus headache?

Symptoms: Fever, significant nasal discharge, facial pain

What to watch for: "A lot of times if your sinuses are acting up without the above symptoms, you may actually have more of a migraine," says Hoyle. In fact, according to studies by the American Headache Society, 88 percent of patients diagnosed with sinus headaches actually had migraines.

What to do: Reach for decongestants and nasal steroid sprays. Consider using a humidifier, vaporizer or neti pot routinely to keep your nasal passages open.

What is a tension headache?

Symptoms: This is the mildest of the bunch and is usually described as a dull ache or a feeling of a band around your entire head.

What to watch for: Tension headaches can become chronic. "That's why we always want to look at the underlying cause," says Stoller. "Is it muscular where the forehead or scalp muscles are in involved? In that case, we like to try biofeedback in which we retain the muscles of the face to stretch or relax."

What to do: Physical therapy can play a role in treating tension headaches, especially when underlying neck issues are in play, Stoller says.

When to worry about a headache

Contact a healthcare professional immediately if you're experiencing an acute headache that comes on like a thunderclap, says Hoyle. "This means you're at zero pain one second and have severe pain one second later," he adds. "That's when we worry about a brain bleed." Other causes for concern: Loss of consciousness associated with a headache or other neurological symptoms, including speech or balance changes, confusion or neck stiffness. All of these things warrant a visit to the ER — stat.