A stroke happens when blood flow to part of the brain is blocked or when bleeding occurs in or around the brain. Symptoms can include sudden face drooping, arm or leg weakness, speech trouble, confusion, vision changes, dizziness, loss of balance, or a sudden severe headache.

Subarachnoid hemorrhage is bleeding in the space around the brain. It often causes a sudden, extremely severe “worst headache,” and may also cause neck stiffness, nausea, vomiting, sensitivity to light, confusion, seizure, or loss of consciousness.

A brain aneurysm is a weak, bulging area in a blood vessel in the brain. Many do not cause symptoms unless they grow, leak, or rupture. Warning signs can include a sudden severe headache, eye pain, double vision, drooping eyelid, nausea, stiff neck, or loss of consciousness.

Dizziness can feel like spinning, lightheadedness, imbalance, or feeling faint. While many causes are not dangerous, sudden dizziness with weakness, trouble speaking, double vision, severe headache, or loss of coordination may suggest a neurological or vascular emergency.

A brain AVM is an abnormal connection between arteries and veins. It may cause headaches, seizures, weakness, numbness, vision changes, or bleeding in the brain. A bleeding AVM can be life-threatening and needs urgent medical care.

Chronic subdural hemorrhage is slow bleeding between the brain and its outer covering, often after head injury, especially in older adults or people taking blood thinners. Symptoms may include headache, confusion, sleepiness, weakness, balance problems, or personality changes.

Headaches and migraines can cause throbbing pain, nausea, light sensitivity, or visual symptoms. Intracranial hypertension means elevated pressure around the brain and may cause headache, blurred or double vision, brief vision blackouts, nausea, and pulsatile tinnitus.

Vertebral artery stenosis or occlusion means narrowing or blockage in arteries that supply the back of the brain. Symptoms may include dizziness, vertigo, double vision, trouble speaking, trouble swallowing, imbalance, weakness, numbness, or stroke-like episodes.

The basilar artery supplies the brainstem and back of the brain. Narrowing or blockage can cause serious symptoms such as vertigo, double vision, slurred speech, weakness, numbness, loss of balance, decreased alertness, or a life-threatening stroke.

The middle cerebral artery supplies large areas of the brain involved in movement, sensation, speech, and vision. Narrowing or blockage can cause one-sided weakness or numbness, facial droop, speech difficulty, confusion, or vision loss.

Bow Hunter Syndrome is a rare condition where turning the head can compress a vertebral artery and reduce blood flow to the back of the brain. Symptoms may include dizziness, fainting, visual changes, vertigo, nausea, or stroke-like episodes triggered by neck rotation.

Pulsatile tinnitus is a rhythmic whooshing, thumping, or pulsing sound that often matches the heartbeat. It can be linked to changes in blood flow near the ear, vascular abnormalities, venous sinus problems, or increased intracranial pressure.

Epilepsy is a neurological condition involving recurrent seizures. Seizures can cause staring spells, abnormal movements, sudden jerks, sensory changes, confusion, loss of awareness, or convulsions, depending on which part of the brain is involved.

Back and neck pain may come from muscles, joints, discs, nerves, arthritis, trauma, or spinal compression fractures. Concerning symptoms include pain with weakness, numbness, trouble walking, bowel or bladder changes, fever, cancer history, or severe trauma.

Trigeminal neuralgia causes sudden, intense facial pain, often described as electric-shock-like, stabbing, or shooting. Pain usually affects one side of the face and may be triggered by chewing, speaking, brushing teeth, touching the face, or cold air.

A dural arteriovenous fistula is an abnormal connection between arteries and veins in the covering of the brain or spine. Symptoms can include pulsatile tinnitus, headache, eye redness or swelling, vision changes, neurological deficits, seizure, or bleeding.

Epistaxis means nosebleed. Most nosebleeds are minor, but severe, recurrent, or difficult-to-control bleeding may require specialist evaluation, especially if related to trauma, blood thinners, vascular abnormalities, tumors, or bleeding disorders.

Head and neck tumors can involve the mouth, throat, nasal cavity, sinuses, salivary glands, skull base, or neck. Symptoms may include a lump, persistent pain, bleeding, swallowing difficulty, voice changes, nasal blockage, or cranial nerve symptoms.

Spinal compression fractures happen when a vertebra collapses, often from osteoporosis, trauma, or cancer. They can cause sudden back pain, height loss, spinal curvature, reduced mobility, and pain that worsens with standing or walking.

Carotid artery stenosis is narrowing of the neck arteries that supply the brain. It may cause no symptoms until a TIA or stroke occurs. Warning signs include sudden one-sided weakness or numbness, speech trouble, vision loss, dizziness, or severe headache.

Idiopathic intracranial hypertension is increased pressure around the brain without a clear cause. Symptoms can include headache, blurred vision, double vision, brief vision loss, pulsatile tinnitus, nausea, and optic nerve swelling that can threaten vision.