Hemicrania continua (HC) is a type of severe headache. It’s different from migraine headaches and cluster headaches. The pain from this uncommon type of headache occurs only on one side of your head or your face. In fact, the name literally means “pain in half the head” in Latin.

This type of severe headache is constant and every day. You don’t have times that you’re without pain. Most of the time the pain stays at a consistent level. Other times, the pain increases in severity quickly, or spikes, for a period.

HC happens mostly to women.

It’s currently not known what causes HC. However, there is some evidence that the use of alcohol or physical exertion may make the pain worse. This syndrome is somewhat newly discovered, and medical professionals are still learning about it and studying it.

The primary treatment for HC is a prescription medication called indomethacin. This medication is a nonsteroidal anti-inflammatory drug (NSAID). It works like naproxen (Aleve, Naprosyn) and ibuprofen (Advil, Motrin IB). However, indomethacin has proven much more effective in relieving the pain of HC, and does so quickly. It has some gastrointestinal side effects that will require you to also take a medication that will reduce acid production and prevent ulcers from forming.

If you aren’t able to tolerate the side effects of indomethacin, your doctor can prescribe alternative medications. These may include:

The symptoms of HC include the following:

  • constant headache pain on one side of your head or face
  • no times when you’re pain-free
  • long-term pain or pain that occurs every day
  • eye tearing on the same side as the pain
  • congested nose or runny nose
  • sweating
  • drooping eyelid only on the same side as the pain
  • eye redness on the same side as the pain

In a small number of cases, the pain may change sides.

Currently, no specific test is available that can diagnose HC. Your doctor will diagnose you primarily based on your symptoms: The pain must be constant, though it may have periodic spikes. The pain is usually only on one side of your head. And you must have these symptoms for three months or more.

Because this pain can mimic other conditions, your doctor may have you get an MRI scan or a CT scan. These tests will rule out other conditions.

Also, as part of the diagnosis, your doctor will want to make sure that your pain responds well to the medication indomethacin, which is used for treating HC. If your pain responds well to this medication, it’s most likely that you have HC. However, an MRI or CT scan may still be needed for your doctor to reach a final diagnosis.

If you have any type of headache that lasts more than three days or you have headaches one or two times every week, you should see a doctor.

Other headache symptoms that should prompt a visit to your doctor include:

  • You need to take an over-the-counter (OTC) pain medication every day for headache pain.
  • The recommended dosage of OTC pain relievers isn’t enough to stop your headache.
  • You have headaches that cause you to be unable to function normally.
  • The severity of your headache pain gets worse.

There are also certain headaches or symptoms combined with a headache that require immediate medical attention:

  • You have a headache that happens all at once and is severe.
  • You experience confusion, stiff neck, or fever with a headache.
  • Your headache is followed by a seizure.
  • You also have double vision, numbness, or speech difficulties along with a headache.
  • You have a headache after you received a head injury.
  • Your headache can’t be stopped with pain medication.

It’s important to maintain regular medical care when you have HC. The treatment of HC with the medication indomethacin is very effective when coupled with regular care from a medical professional.

Most people with HC are able to live without any or very little HC pain when treated with indomethacin as well as any preventive medications or treatments their doctor may recommend.

However, if you aren’t able to use indomethacin for a long time, your doctor may need to switch you over to an NSAID. NSAIDs aren’t as effective at relieving the pain of HC but may still help.