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A headache can range from mild discomfort to debilitating pain that keeps you from performing your daily tasks. It may seem like your brain is hurting, but a headache actually stems from the compression of blood vessels, nerves, and muscles in the head, neck, or face.
The nerves in the cranium (in and around the brain) are highly sensitive to pain and can get affected by muscle tension, tightening of the blood vessels due to inflammation, stress, and other such triggers. These intracranial nerves then send pain signals to the brain, resulting in a headache.
What Is a Headache?
A headache is a common condition of the nervous system, defined as a painful sensation in the head region. Headaches can be divided into two categories:
1. Primary headache syndromes
These headaches are not indicative of another disorder. Primary headaches, when mild, can self-resolve or can be treated by over-the-counter medications.
2. Secondary headache syndromes
These headaches are a result of another disease process. Secondary headaches require further immediate evaluation to find and treat the underlying cause.
Different Types of Headaches
The most common types of primary headaches syndromes are tension-type headaches and migraine headaches. Cluster headaches are another type of primary headache.
1. Migraine headache
Migraine headaches are characterized by throbbing pain on one side of the head and are frequently associated with nausea and vomiting. Migraines are often worsened by physical exertion, light, and sound.
Migraines affect millions of people per year and frequent and/or severe migraine headaches often require medical evaluation for diagnosis and effective treatment. (1)
2. Tension-type headache
Tension-type headaches involve pain typically on both sides of the head. (1) The pain is often described as a “tight band” of pain around the head. Tension-type headaches can be infrequent, mild, and self-resolving or frequent, chronic, and requiring medical intervention.
3. Cluster headache
Cluster headache involves severe pain around the eye, typically on one side. It can have associated tearing and/or redness of the eye, a runny nostril, and sweating and/or skin changes.
People with cluster headaches experience excruciating pain that often disrupts sleep. Due to the severity of symptoms, they most often require medical evaluation and treatment to relieve the symptoms. (1)
What Makes a Headache Potentially Dangerous?
Although headaches are common, several warning signs and symptoms indicate an emergency condition that requires immediate medical attention.
Headache, especially in the presence of the following warning signs, can indicate a stroke and should be evaluated immediately. Remember the acronym FAST for stroke: face drooping, arm weakness, speech changes, and time to call 911. (2)
1. Face drooping/facial weakness
Facial weakness, especially on one side, can be a sign of ischemic or hemorrhagic stroke. Ischemic stroke results from an obstruction of blood flow to a vessel in the brain, whereas hemorrhagic stroke results from a rupture of a blood vessel in the brain.
2. Arm weakness/leg weakness
Weakness in the extremities can also be a sign of stroke. If extremity weakness occurs with or without headache, a stroke evaluation is needed to determine the cause.
People with headache and extremity weakness should be evaluated through a neurological examination and brain imaging (CT scan and/or MRI of the brain).
3. Speech difficulty/speech changes
Changes in speech can be seen with stroke. Dysarthria, or slurred speech, is a common symptom of stroke. Aphasia, or difficulty with comprehending and producing speech, is also a common symptom of stroke.
When headache is accompanied by speech changes, evaluation for stroke through examination and brain imaging should occur immediately. Remember FAST and call 911!
4. Vision loss
Headache accompanied by vision loss or vision changes can be a sign of a stroke. Vision loss can be a result of a stroke affecting the brain or the optic nerve, the nerve that carries visual input from the eye to the brain.
Headache with vision changes could also be related to temporal arteritis (TA), (3) a vessel disorder in which inflammation in the temporal artery leads to headache, jaw pain, and often vision loss if not treated immediately.
5. Neck pain
Headache associated with severe neck pain can be associated with tearing of the wall of an artery in the neck, often also known as vessel dissection. This is commonly seen in the setting of a neck injury, trauma, or manipulation to the neck and requires medical and, in some cases, surgical intervention for treatment.
Headache and neck pain and/or stiffness can also be a sign of meningitis, an infectious process of the covering (meninges) of the brain and spinal cord. This would be suspected, especially when accompanied by fever, and would be evaluated further using brain imaging, bloodwork, and a spinal tap (lumbar puncture).
Headache with an associated fever is often seen in many infectious processes. As mentioned, a headache with a fever may indicate meningitis, encephalitis, or brain inflammation.
Headaches with fever can also be a sign of many bacterial, viral, or inflammatory processes occurring throughout the body. Those with a flu virus infection often report fever, headaches, and muscle aches.
More recently, there has been evidence noting that people with COVID-19 may present with a headache and other neurological disorders. (4)
Headache accompanied by confusion can be seen in various underlying conditions: stroke, seizures (most often after a seizure occurs or during the “post-ictal” state), infectious and inflammatory diseases of the brain, and viral and bacterial infections in the body.
Headaches with associated confusion can also occur in severe hypertension, liver failure, and kidney dysfunction.
8. Sudden-onset and severe headache
A sudden-onset and severe headache, especially in people without a history of headache, may be associated with subarachnoid hemorrhage.
Subarachnoid hemorrhage is a type of hemorrhagic stroke that leads to bleeding in the subarachnoid space, a region surrounding the brain. This type of hemorrhage is often secondary to vessel abnormalities, including vessel aneurysm and arteriovenous malformation.
People with subarachnoid hemorrhage often describe the onset of the headache as “the worst headache of one’s life” and a “thunderclap headache” due to its rapid onset. A headache that may indicate subarachnoid hemorrhage should be evaluated immediately using brain imaging.
Headaches are common neurological conditions affecting millions of people per year. Many mild headaches self-resolve or can be treated with over-the-counter medications with relief.
However, there are several signs and symptoms that you should not ignore with a headache, as they may indicate a serious condition requiring immediate medical attention.
As always, if you are concerned about a medical problem, contact your healthcare provider, and please contact your emergency facility in the event of an emergency.