Headaches can cause a dull throbbing or an intense ache and pain in different areas, including the right side of your scalp, base of your skull, and your neck, teeth, or eyes.

While headaches can be uncomfortable, they’re unlikely to be “brain pain.” The brain and skull don’t have nerve endings, so they won’t cause pain directly. Instead, a wide range of factors can affect headaches, from lack of sleep to caffeine withdrawal.

Causes of headaches on the right side
Lifestyle factors

Headaches are most commonly caused from factors like:

skipping meals
muscle problems in your neck
medication side effects, such as long-term use of over-the-counter (OTC) pain medicine
Infections and allergies

Sinus infections and allergies can also cause headaches. Headaches resulting from sinus infections are the result of inflammation, which leads to pressure and pain behind your cheekbones and forehead.

Medication overuse

Excessive use of medication to treat headaches can actually cause headaches. This is the most common secondary headache disorder, and it affects up to 5 percentTrusted Source of the population. Medication overuse headaches tend to be worst upon awakening.

Neurological causes

Occipital neuralgia: There are two occipital nerves in the spine of your upper neck that run through the muscles to your scalp. Irritation of one of these nerves can cause shooting, electric, or tingling pain. Often the pain will be on only one side of your head.

Temporal arteritis: This is a condition in which you have inflamed or damaged arteries that supply blood to your head and brain. This pressure can cause other symptoms such as vision impairment, shoulder or hip pain, jaw pain, and weight loss.

Trigeminal neuralgia: This is a chronic condition that affects the nerve that carries sensation from your face to your brain. The slightest stimulation on your face may trigger a jolt of pain.

Other causes

More serious causes of headaches that can occur on only one side include:

tumors, which can be both benign or malignant (cancerous)
Only a doctor can diagnose the cause of your headaches.

Types of headaches
There are different types of headaches, each of which has different causes and symptoms. Knowing which type of headache you have can help your doctor diagnose the cause.

Tension headaches

Tension headaches are the most common type of headache, occurring in about 75 percent of adults. While they usually affect both sides, they can also be unilateral, or occurring on only one side of your head.

Feels like: A dull ache or a squeezing pain. Your shoulders and neck can also be affected.

Migraine headaches

Migraines can occur on one or both sides of your head, and can result in light and sound sensitivity, nausea and vomiting, blurred vision, or paresthesia.

Feels like: A severe throbbing or pulsating sensation.

Before or during a migraine, some people will experience “auras,” which are most often visual. Auras can have positive or negative symptoms. Positive symptoms are due to activation of the central nervous system. Examples of positive symptoms include:

vision disturbances like zigzag vision or flashes of light
auditory problems like tinnitus or noises
somatosensory symptoms such as burning or pain
motor abnormalities like jerking or repetitive movements
Negative symptoms are manifested as a loss of function, which includes loss of vision, loss of hearing, or paralysis.

Cluster headaches

Cluster headaches are often painful and involve only one side of your head. You may also experience restlessness, pale or flushed skin, redness of the affected eye, and a runny nose on the affected side of your face.

Feels like: Intense pain, especially eye pain involving only one eye and radiating to areas of your neck, face, head, and shoulders.

Chronic headaches

Chronic headaches occur 15 or more days a month. They can be tension headaches or chronic migraines. Make an appointment with your doctor to diagnose the cause, if you’re experiencing chronic headaches.

When to see a doctor
In rare cases, headaches can be an emergency symptom. Seek medical attention immediately if you experience a headache following a trauma, or have a headache along with any of the following symptoms:

stiff neck
vision loss
double vision
slurred symptoms
pain near your temples
increasing pain when moving or coughing
You may also want to visit your doctor if the headache is sudden and severe, wakes you up at night, or gets increasingly worse.

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How your doctor will diagnose your headache
Make an appointment to see your doctor if you’re experiencing a change in the frequency or severity of your headaches.

When you go in to see your doctor, they’ll conduct a physical exam, and ask about your medical history and any symptoms you may be experiencing.

You can prepare for this by having answers to the following:

When did the pain start?
What other symptoms are you experiencing?
Is the headache the first symptom?
How often are you experiencing the headaches? Are they a daily occurrence?
Do you have a family history of headaches, migraines, or other relevant conditions?
Do you notice any obvious triggers?
Your doctor will likely run different tests to give you a definitive diagnosis. The tests they may run include:

blood tests, to look for infections of the spinal cord or brain, toxins, or blood vessel problems
cranial CT scans, to get a cross-sectional view of your brain, which can help diagnose infections, tumors, bleeding in your brain, and brain damage.
head MRI scans, to reveal detailed images of blood vessels and your brain including abnormalities in your brain and nervous system, bleeding in your brain, strokes, problems with blood vessels, and infections.