Should I Worry About a Headache Only on One Side?

Q: Should I worry if I get a headache only one one side?

A: Headaches can come in many forms. Because the way you experience headaches can vary (and so do their underlying causes), you should make sure you’re paying close attention to how the headaches are affecting you.

If you’re getting headaches only on one side of your head you shouldn’t worry, but you should make an appointment with your doctor. One-sided headaches can mean different things. But they often point to a group of disorders that will need a thorough exam to provide treatment.

According to headache specialist Emad Estemalik, MD, there are additional questions your doctor will focus on to identify what’s causing your one-sided headaches.

First, are the headaches continuous or do they come and go? And second, how long do the headaches last? Your answers help your doctor narrow down which category your headaches fall under.

Categories of one-sided headache disorders

When we talk about unilateral or one-sided headaches, there’s a distinct family of headache disorders trigeminal autonomic cephalgias (or TACs). There are four distinct types of headaches:

1. Cluster headache — This type more often affects men. These headache attacks can occur around certain seasons. They last 15 to 180 minutes. They’re so severe and sharp that patients sometimes call them suicide headaches.
2. Hemicrania continua headache — This headache causes continuous pain on one side of the head for 24 hours while also causing sharp attacks of pain. A person will get a runny nose and may also have teary eyes.
3. Paroxysmal hemicrania headache — This one is similar to hemicrania continua, but people will get shorter attacks that last less than 24 hours, and they will be pain-free in between.
4. SUNCT and SUNA — These stand for short-lasting unilateral neuralgiform headache with donjunctival injection and tearing, and short-lasting unilateral neuralgiform headache with cranial autonomic symptoms. They are short-lasting headaches that rarely affect people. They cause a few seconds of severe head pain on one side of the head with teary eyes and runny nose.

“If you have one-sided headaches, it really is important to seek an evaluation by a neurologist or a headache specialist,” Dr. Est​emalik says. “A thorough exam is crucial for the proper treatment and brain imaging is often necessary to rule out any secondary causes.”