Different headache types can cause pain on the left side of the head. The pain usually isn’t cause for worry. But if the pain is intense or doesn’t go away, there may be a more serious cause.

There are many different kinds of headaches, from migraine to tension. There are also various reasons you might have pain or pressure only on the left side of your head.

That said, though headaches can affect one or both sides of the head, having a headache on the left side is not a trademark of any specific condition.

Keep reading to learn about the possible causes and when to call your doctor.

Tension headaches are the most common type of headache worldwide. They affect about 75% of adults.

Feels like:

This feels like a band tightening around your head, squeezing your face and scalp. You can feel the pressure along one or both sides and the back of your head. Your shoulders and neck might also be sore.

Migraine is one of the most common disorders in the world and affects about 1 in 6 people in the United States. Women are two to three times more likely to experience migraine attacks than men.

Feels like:

This feels like an intense, throbbing pain, often on one side of the head. The pain is often accompanied by symptoms like nausea, vomiting, and sound and light sensitivity.

Cluster headaches are rare but intensely painful headaches that are more common in men. Women may experience more severe symptoms, though this finding is limited to only one study, and more research is necessary.

Feels like:

As the name suggests, cluster headaches arrive in clusters over days or weeks. These cluster attacks are followed by remissions — headache-free periods lasting for months or years.

When you experience one, you’ll feel intense pain on one side of your head. The eye on your affected side might be red, watery, and painful.

Sinus headaches are severe headaches caused by an infection in the sinuses (sinusitis) and accompanying inflammation. They’re usually mild-to-moderate in intensity, but less often may be severe. In this case, the infection may be more serious and warrants extra examination by a doctor.

Feels like:

Sinus headaches feel like diffuse pressure behind the eyes, at the sides of the nose, and sometimes even just above the teeth. They are usually accompanied by congestion, stuffiness, or postnasal drip.

They may cause eye pain, ear discomfort, and a headache on both sides of the head. Sometimes the headache can be isolated to one side.

Chronic headaches can be any type — including migraine or tension headaches. They’re called chronic because they happen at least 15 days a month for 6 months or more.

Feels like:

These feel like a dull throbbing pain, intense pain on one side of the head, or a vice-like squeezing, depending on which type of headache you get.

A cervicogenic headache is when you experience a headache caused by a problem in your neck. It can be caused by different conditions such as osteoarthritis, an injury, or even poor posture.

Feels like:

One of the key symptoms of this condition is a headache on one side of your face or head. You may also feel pain around your eye. Your neck will also usually feel sore.

Hemicrania continua is a severe headache affecting only one side of the head, either the left or the right.

Feels like:

What’s different about this headache type is the constant and chronic pain. You’re always in pain; no time comes when the headache subsides. It typically stays at a consistent level but may spike occasionally.

Short-lasting, unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and unilateral neuralgiform headache with autonomic symptoms (SUNA) are similar headache types. They always occur on one side of the head.

These headaches are quite rare, with a prevalence of only 6.6 per 100,000. The cause is not fully understood.

Feels like:

SUNCT or SUNA usually feel like sharp, stabbing, or burning short-burst pains. They will often be accompanied by symptoms like nasal congestion and swollen eyes.

A hypnic headache develops when you sleep, often causing you to wake up. 1 out of 3 people who get these headaches will experience severe pain.

Feels like:

This headache can affect one or both sides of your head. The pain can be a dull throbbing but may feel sharp and stabbing.

New daily persistent headache (NDPH) develops suddenly but reoccurs often after you get it the first time. It can affect one or both sides of the head.

Feels like:

This headache feels throbbing and is similar to a tension headache. But what distinguishes it is that you can remember the exact day or time you first developed it.

A post-traumatic headache can occur after a head injury.

Feels like:

This can feel like a migraine headache, and researchers suspect that head injuries may trigger migraine headaches, though this is not fully established.

You may feel pain on one side of your head, which can worsen if you exert yourself. You may also be sensitive to light.

Many things can trigger headaches. They range from lifestyle factors like skipping meals to overusing medications, though none of them are specific to the headaches on the left side.

Lifestyle factors

If you experience frequent headaches, changing your lifestyle may greatly ease your symptoms. Any of these factors can trigger a headache:

  • drinking alcohol
  • skipping meals
  • being stressed
  • not getting enough sleep

In addition, eating processed foods containing certain food preservatives or artificial dyes may trigger headaches in some people.

Medical triggers

Serious medical conditions:

There are a few serious medical conditions that can trigger a one-sided headache. These include:

  • Vertebral or carotid artery dissection: Artery dissection is a life threatening condition when your artery tears from the inside. This can lead to a stroke. Carotid artery dissection often presents with a headache on one side of the head, as does a dissection of the vertebral artery, which runs in the upper part of the spine at the brainstem.
  • Brain aneurysm: Brain aneurysm is life threatening because it can rupture. People experience symptoms before rupturing in only 10–15% of cases. One possible symptom is a headache above or behind one of your eyes.
  • : This is a type of vasculitis that can cause a throbbing headache on one side of the head and sometimes on the back of the head. The scalp area will also feel tender to the touch.
  • Meningitis: This is inflammation caused by infection of the meninges, which is the lining around the brain and spinal cord. It’s usually caused by a virus but can be caused by bacteria, which is typically more severe. It commonly causes a headache covering the entire head but rarely affects one side only.
  • Encephalitis: This is inflammation of the brain tissue. One of the symptoms is a headache, which can be one-sided in rare cases.
  • Brain tumor: This is brain cancer. Some tumors, especially if they metastasize, can cause a headache on one or both sides of the head.
  • Cerebrospinal fluid (CSF) leak: This is when brain fluid leaks out of the meninges surrounding the brain and spinal cord. It may heal on its own, usually after a few weeks, but severe traumatic tears may need a procedure to repair.

Headaches on one or both sides of the head are common and usually don’t have a serious cause. But sometimes, they can signal a more serious problem. Call your doctor or get emergency help if:

  • the pain feels like the worst headache of your life
  • you’ve had a change in the pattern or severity of your headaches
  • the headaches wake you up at night
  • the headaches started after a blow to the head
  • confusion
  • fever
  • stiff neck
  • vision changes
  • double vision
  • pain that increases when you move or cough
  • numbness, weakness
  • pain and redness in your eye
  • loss of consciousness

How do I get rid of a headache on my left side?

How to treat a headache on the left side of your head can depend on the cause. Sometimes, drinking water, resting, or eating something can help relieve a headache. But if the pain is severe, long lasting, or doesn’t respond to over-the-counter (OTC) pain relievers, you may need medical attention.

What is a headache on one side of the head?

You can experience a headache on one side of the head or both sides of the head. Many conditions, such as dehydration, stress, migraine, and sinus congestion, can cause a headache on one side of the head. Serious causes can also include brain inflammation, severe infection, and brain cancer.

What does a dehydration headache feel like?

A headache caused by dehydration may feel like a tension headache. People may describe a tension headache as a band tightening around the head, squeezing the face and scalp. You may feel pressure on one or both sides and the back of your head. Dehydration may also trigger migraine. A migraine episode can feel like an intense, throbbing pain, often on one side of the head that may occur with nausea, vomiting, and sound and light sensitivity.

What is a severe headache behind the left eye?

A severe headache behind the left eye may result from serious conditions, such as a brain aneurysm, that require emergency medical care. Other conditions, including sinus pressure, migraine, and a cervicogenic headache may also cause a headache behind one eye.

A few different types of headaches cause pain on only one side of your head. You can usually relieve these headaches with over-the-counter medications and lifestyle changes like more rest.

See your doctor for severe headaches that interfere with your life. Your doctor can discover what’s causing your headaches and recommend treatments to help manage your pain.

Get emergency medical attention if you experience any neurological symptoms. Learn how to know when to be concerned about a headache.

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