Learn about the symptoms and treatment options of these rare headache disorders and how they differ from migraine.

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT syndrome) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA) are rare headache disorders. As their names suggest, they involve short, intense bursts of pain on one side of the head, primarily around one eye. There are also involuntary symptoms like eyelid drooping, tearing, nasal stuffiness and facial sweating.

These headache disorders more commonly affect men and have an average onset of 50 years old. To be clear, SUNCT and SUNA are not migraine diagnoses. They are in the family of headache disorders called TACs.

What is the TACs family?

Trigeminal autonomic cephalgias, or TACs, are primary headache disorders characterized by unilateral (one-sided) pain in the face or head. The pain stems from the trigeminal nerve, which sends messages between your face and your brain and has three branches to the eye and forehead, cheek and lower jaw. Because of the location of symptoms, people can confuse these headache disorders for sinus conditions, dental pain or  trigeminal neuralgia.

TACs include cluster headaches, hemicrania continua, paroxysmal hemicrania and SUNCT and SUNA headache. Though they are similar, TACs have slightly different clinical symptoms and responses to treatment.

Cluster Headache

A cluster headache is marked by headaches that occur daily or a few times a day for a few weeks or months before stopping. Symptoms of a cluster headache include sharp, stabbing pain on one side of the head, often behind one eye, for intense 15-minute to 3-hour bursts. They affect 0.1% of people globally and affect more men than women.

Hemicrania Continua

Hemicrania continua also involves pain on one side of the head, but it causes constant long-lasting pain. The pain may worsen or spike for specific periods, but it doesn’t completely go away. Hemicrania continua occurs more commonly in women than men.

Paroxysmal hemicrania is a separate but related disorder that includes a one-sided headache. But it causes five or more attacks of severe pain lasting up to 30 minutes over a single day.


Doctors also include SUNCT and SUNA in the TACs. It can be challenging to differentiate between the headache disorders within the TAC family. Still, SUNCT and SUNA typically cause attacks that are shorter in duration and more frequent within a day’s time than the other TACs. Taking note of all of your symptoms and their locations, as well as the duration, frequency and intensity of attacks will help you and your doctor pinpoint a diagnosis and appropriate treatment.

While TACs are headache disorders, they are different from migraine. The main distinction is that symptoms of TACs almost always present on one side of the head and face. TACs always involve head pain, while migraine may or may not. Unlike migraine, TACs don’t have symptoms like nausea, vomiting or sensitivity to light or sound. Instead, they involve autonomic symptoms like nasal congestion or runny nose, facial flushing or sweating and watery eyes on one side of the face.

Symptoms of SUNCT and SUNA

SUNCT and SUNA involve pain of moderate to severe intensity that occurs around one eye or temple in bursts of five seconds to five minutes per episode. Attacks usually always happen during the daytime. People with these headache disorders may have multiple attacks within an hour and as many as 3 to 200 attacks in one day. The pain can feel like burning, stabbing, throbbing or electric.

Attacks also include other autonomic symptoms, such as forehead sweating, pressure around the affected eye, eyelid swelling and eye tearing on the affected side of the face.

SUNCT and SUNA are similar. There is a slight distinction in that SUNCT syndrome involves the two autonomic symptoms of eye redness and tearing, while SUNA can involve any of the autonomic symptoms. SUNA can also have slightly longer-lasting attacks, averaging 10 minutes.

Treatment Options for SUNCT and SUNA

TACs are often resistant to therapies typically used for short-lasting headaches. Because of their unpredictable timing and pattern, it can be difficult to treat them effectively. It also makes it hard to assess whether a treatment is working. Two notable exceptions: Hemicrania continua and paroxysmal hemicrania, which involves longer-lasting head pain, can resolve with daily indomethacin treatment.

Some medications, such as corticosteroids or anti-seizure drugs, may help prevent TAC headache attacks or relieve symptoms. Lamotrigine and gabapentin are two medications commonly used for treatment. Intravenous (IV) lidocaine or injections to block nerve signaling may provide temporary relief during acute attacks. If conventional medications and non-drug therapies do not help manage these headache disorders, surgery for simulator placement may be an option to consider.

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