The nervous system is the body’s communication and control network. It includes the brain, spinal cord and nerves and helps regulate movement, sensation, thinking, memory, speech, breathing and many other functions.
Common brain and nervous system conditions
- Stroke — brain injury caused by interrupted blood flow or bleeding in the brain.
- Transient Ischemic Attack (TIA) — temporary stroke-like symptoms requiring urgent assessment.
- Epilepsy — a neurological disorder characterized by a lasting tendency to have unprovoked seizures.
- Multiple Sclerosis (MS) — an immune-mediated disease affecting the brain and spinal cord.
- Parkinson’s Disease — a progressive neurological disorder affecting movement and other body functions.
- Dementia — cognitive decline severe enough to interfere with everyday life.
- Peripheral Neuropathy — damage to peripheral nerves that can cause numbness, pain or weakness.
- Encephalitis — inflammation of the brain that can cause confusion, seizures and other neurological symptoms.
- Meningitis — inflammation of the membranes around the brain and spinal cord.
- Migraine — a neurological disorder that can cause recurrent headache, nausea and sensitivity to light or sound.
- Headache — an overview of common headache types and warning signs.
- Tension Headache — a common headache type often causing pressure or tightness around the head.
- Cluster Headache — severe attacks of pain, usually around one eye.
- Concussion — a mild traumatic brain injury.
- Sciatica — pain and neurological symptoms caused by irritation or compression affecting the sciatic nerve.
- Herniated Disc — a spinal disc problem that can irritate nearby nerves.
- Narcolepsy — a neurological sleep disorder affecting control of sleep and wakefulness.
Symptoms that need urgent attention
Seek emergency help for sudden facial weakness, weakness or numbness in an arm or leg, new speech difficulty, sudden loss of vision, a first seizure, loss of consciousness, severe head injury, a sudden extremely severe headache or rapidly worsening weakness or breathing difficulty.
Recognizing a possible stroke
- Face: one side may droop or feel weak.
- Arms: one arm may be weak or difficult to raise.
- Speech: speech may be slurred, confused or difficult.
- Time: contact your local emergency services immediately.
Stroke symptoms can improve or disappear, but urgent medical assessment is still necessary because this may be a TIA.
Assessment and treatment
Diagnosis depends on symptoms and may involve a neurological examination, blood tests, CT or MRI imaging, electrical tests or other specialist investigations. Treatment varies by condition and may include medicines, surgery, rehabilitation, physical therapy, occupational therapy, speech therapy or psychological support.
Sources and further reading
Last reviewed: 4 September 2026. This page provides general health information and does not replace individual medical assessment or treatment.