10 Headache Symptoms You Shouldn't Ignore

​2. A ‘thunderclap’ onset​

This is a severe headache that comes on suddenly (“like being struck by thunder,” Carver says) and feels like the worst headache of your life.

Especially if the pain starts when you’re exerting yourself physically, this type of headache may be a sign of a ruptured blood vessel in your brain called an aneurysm. Other symptoms include neck stiffness or an altered mental state. It’s important to get help fast because a ruptured aneurysm causes bleeding that can quickly become life-threatening, Carver says.

A thunderclap headache may also be a stroke symptom, particularly if it’s paired with confusion, trouble talking or weakness on one side.​​

3. Temple tenderness or pain

​If you are over age 50 and have a throbbing headache that’s concentrated in the temple area, you may have a condition called giant cell arteritis, or temporal arteritis, which means the blood vessels in your head are inflamed. Other symptoms include jaw pain or trouble chewing, tenderness of your scalp or temples, fatigue, flu-like symptoms or vision changes. The condition is more common in women than men.

A headache caused by giant cell arteritis may progressively worsen or it may go away and come back. Either way, it’s important to get it checked out quickly, says MaryAnn Mays, M.D., a neurologist at Cleveland Clinic. “It can cause a sudden loss of vision if you don’t catch it in time,” she says.​​

4. Ache after a head injury (especially if you’re on blood thinners)​

If you notice a headache several hours or even several days after hitting your head, it could be the first sign of dangerous bleeding inside your skull, known as a subdural hematoma, Mays says.​​

​​“It may have been a week ago since you fell, but you can get some delayed bleeding, especially if you’re on blood thinners,” Mays says. “Even if you’re not on blood thinners, any older adult who has had a recent fall and then gets a headache definitely needs to be evaluated right away. Doing so can be life saving.”​​Other signs of a hematoma are confusion, weakness and fainting. Symptoms typically worsen over time.​​

5. Headache after starting a new medication

A headache is a common side effect of many medications, but many patients don’t realize it, Mays says. “The first instinct of a patient is to get another drug to fix their headache, and that’s how you end up with patients on multiple medications,” she says. If you develop regular headaches after starting a new prescription, talk to your doctor about whether there could be a link. (Don’t stop taking a prescription unless your doctor says it’s OK.) Drugs that commonly cause headaches include antidepressants, heart medications and erectile dysfunction drugs.

6. Tooth or face discomfort

​If your pain seems to be in your face and feels at times like an electric shock, you may have a nerve problem known as trigeminal neuralgia. The pain may be triggered by chewing, washing your face or brushing your teeth. While the condition can be treated with medication, it sometimes takes a while to get diagnosed, Mays says. “At first, the pain may seem like it’s in a tooth, so patients often go to the dentist. Sometimes, patients undergo root canals that are unnecessary.”​​

7. Vision problems​

An ache that feels like it’s in or around one eye — especially if accompanied by vision problems — can signal acute glaucoma (also called closed-angle glaucoma). Unlike open-angle glaucoma, which progresses slowly and without symptoms, acute glaucoma is a sudden buildup of pressure or fluid in the eye that damages the optic nerve. It’s an emergency that can lead to complete vision loss within 48 hours, so it’s important to get to a hospital quickly.​​

8. Pain when you wake up​

The most common diagnosis in older people who wake up with a headache is sleep apnea, Carver says. Sleep apnea typically causes a morning headache that gets better as the day goes on. You may also feel tired during the day. It’s important to be evaluated if you think you may have sleep apnea because if it’s not controlled, you are at greater risk of stroke and heart attack.

Morning headaches can be a sign of other problems, including a brain tumor, neck arthritis or medication withdrawal. If you have a history of cancer, a morning headache may indicate a neoplasm in the brain.

9. Headache shared by others in the house

Carbon monoxide poisoning could be the culprit if others in your household are also complaining of headaches, Mays says. If your headache goes away when you leave the house, that’s another clue there could be carbon monoxide in your home. Headache is the most commonly reported symptom of carbon monoxide poisoning. Other signs include dizziness, weakness, nausea, vomiting, chest pain and confusion. Carbon monoxide (CO) is an odorless gas that can be deadly if you breathe in enough of it.

You should have a battery-operated or battery-backup CO detector in your home. The Centers for Disease Control and Prevention recommends replacing the battery when you change the time on your clocks each fall and spring.

10. Additional neurological issues

​It probably goes without saying that if along with your headache you have any confusion, memory problems, seizures, muscle weakness, numbness or trouble talking, that is a reason for concern, Carver says. Those are all neurological symptoms that indicate something is going on inside your brain, whether it’s inflammation, infection or a tumor. Your health care provider can order a scan and other tests to make a definitive diagnosis.​​

Editor's Note: This article, originally published on August 25, 2021, has been updated to reflect new information.